June 1, 2026 · ~25 min read · Oregon · Washington State · Montgomery County MD · California

Oregon SB 611, Washington HB 1217, Montgomery County Bill 15-23, and California AB 1482 in 2026 — four rolling new-construction exemption rent caps compared, head-to-head

Four U.S. rent-cap regimes share a structural mechanism that no other state or local law uses: a rolling new-construction exemption tied to the age of each building individually. A building exempt today because it is nine years old will become covered the day it crosses the regime’s threshold — and will stay covered forever after. Oregon SB 611 and California AB 1482 each use a 15-year window. Washington State HB 1217, the newest of the four (signed May 7, 2025), uses a 12-year window — the shortest. Montgomery County Bill 15-23 uses a 23-year window — the longest. Despite sharing the rolling mechanism, the four regimes arrive at radically different cap levels in 2026: Oregon 9.5%, Washington 9.683%, California ≈ 8%, Montgomery County 5.8% — because they use different CPI anchors, different base additives, and different ceiling rules. In this post we walk each regime’s statute, formula, CPI anchor, window length, graduation-day mechanics, notice rules, vacancy treatment, and penalty structure side by side.

Quick orientation: the four rolling-exemption regimes in 2026

The table below summarizes the structural parameters of all four regimes. The two columns that matter most for initial coverage analysis are the window length (which housing stock is exempt right now) and the cap level (how much the rent can rise once coverage attaches).

Three structural patterns jump out of that table immediately. First, Oregon and Washington use nearly identical formulas — min(7% + CPI, 10%) — but arrive at different 2026 caps (9.5% vs. 9.683%) because they measure CPI over different geographies (West Region vs. Seattle MSA) and different time windows. Second, Montgomery County’s formula (CPI + 3%) carries the smallest base additive of the four and the tightest ceiling (6%), producing the lowest 2026 cap (5.8%) despite using a longer rolling window than Oregon or California. Third, California is the only regime with a 30-day notice option — all three others require 90 days for every increase. We develop each of these observations in detail below.

What “rolling” means: graduation day mechanics across all four regimes

Before walking each regime’s statute, it is worth establishing precisely what “rolling” means and how coverage attaches in practice.

A rolling first-certificate-of-occupancy exemption exempts a building from the rent cap for a fixed number of years after its first certificate of occupancy (or comparable occupancy permit) was issued, then removes the exemption permanently on the day the building crosses that threshold. The exemption is tied to each building individually, not to a single calendar date. This distinguishes rolling exemptions from California’s Costa-Hawkins permanent carve-out (Cal. Civ. Code §1954.52(a)(1)), which exempts all buildings with first CoC on or after February 1, 1995 from local rent control — and will continue to exempt those buildings forever, even when they are 100 years old.

Under a rolling regime, graduation day — the moment coverage first attaches to a building — is the specific date that falls exactly the window length after the first CoC (or U&O permit) was issued. For a 15-year window, a building issued first CoC on March 15, 2011 graduated on March 15, 2026. Once graduated, the building stays covered; there is no mechanism by which coverage lapses or un-attaches. The following are the precise triggering provisions in each of the four statutes:

• Oregon (15-year): ORS §90.323(2)(a) exempts “a dwelling unit for which the first certificate of occupancy for the unit was issued less than 15 years before the date of the notice of the rent increase.” The trigger is the notice date, not the effective date. A building issued first CoC on April 1, 2011 would have its exemption lapse for any increase notice served on or after April 1, 2026 — even if the effective date of that increase extends further into 2026.
• Washington (12-year): RCW §59.18.700(2)(d) exempts a dwelling unit “for which the first certificate of occupancy was issued less than 12 years before the proposed effective date of the rent increase.” Unlike Oregon, Washington’s trigger is the effective date of the increase, not the notice date. A building issued first CoC on September 1, 2014 is exempt for any increase whose effective date is before September 1, 2026, but covered for any increase effective on or after September 1, 2026, regardless of when the 90-day notice was served.
• Montgomery County (23-year): Bill 15-23 (MC Code Chapter 29, Article VII) uses the phrase “use-and-occupancy (U&O) permit” rather than “certificate of occupancy,” reflecting Maryland permit-law terminology. A dwelling unit is exempt if its first U&O permit was issued less than 23 years before the proposed effective date of the rent increase. The 23-year threshold is the longest rolling window among the four regimes. A building permitted January 15, 2003 graduated on January 15, 2026 and is now covered for any increase with an effective date on or after that date.
• California (15-year): Cal. Civ. Code §1947.12(d)(4)(A) exempts a unit for which “the certificate of occupancy or other proof of compliance with applicable building codes for the residential real property was issued within the 15 years prior to the date of the notice of the rent increase.” Like Oregon, the California trigger is the notice date. A building issued first CoC on July 1, 2011 is exempt for notices served through June 30, 2026, and covered for notices served on or after July 1, 2026.

The Oregon/California notice-date trigger versus the Washington/Montgomery County effective-date trigger creates a practical planning difference. For a landlord whose building is approaching its window threshold: under Oregon and California, serving notice one day before the building’s 15-year anniversary locks in the exemption for that increase, even if the 90-day notice period pushes the effective date past the anniversary. Under Washington and Montgomery County, serving notice before the anniversary provides no advantage if the effective date falls after the anniversary — the cap will apply to that increase.

Oregon SB 608 → SB 611 (ORS §90.323): the 15-year window, 9.5% cap

Oregon made history in February 2019 when Governor Kate Brown signed Senate Bill 608, establishing the first modern statewide rent-cap law in the United States. The original SB 608 formula tied the annual rent-increase cap to the West-Region Consumer Price Index plus a 7-percentage-point base additive, producing a cap that moved with regional inflation while maintaining a floor that kept pace with landlord operating costs. The 15-year rolling new-construction exemption at ORS §90.323(2)(a) was written into SB 608 from the outset, balancing tenant protection against the concern that capping rents on new buildings would chill apartment construction.

When CPI surged in the post-pandemic inflation cycle — the West-Region CPI measuring approximately 5-6% in 2022 and 2023 — the uncapped formula would have produced rent-cap ceilings of 12-13%. In 2023 the Oregon Legislature passed Senate Bill 611, signed by Governor Tina Kotek, which restructured the formula to explicitly state the 10% maximum: the annual cap is now the lower of (a) 10% or (b) 7% plus the West-Region CPI, published annually by the Oregon Department of Administrative Services. SB 611 preserved the 15-year rolling exemption unchanged and made no changes to the notice-period requirements or penalty structure.

The 2026 Oregon cap: 9.5%

For calendar year 2026, the Oregon Department of Administrative Services published a West-Region CPI reading of approximately 2.5%, producing a formula result of 7% + 2.5% = 9.5% — below the 10% ceiling, so the cap is 9.5%. This cap applies to any qualifying rent increase with an effective date in calendar year 2026, provided the applicable notice was served on or after January 1, 2026 (or the notice was served in late 2025 with a 2026 effective date — the notice-date trigger means the cap at the time of the notice date controls for Oregon).

The Oregon Department of Administrative Services publishes the official annual cap each September, derived from the BLS CPI-U West Region, 12-month change to approximately the middle of the calendar year preceding the cap year. For a landlord planning increases in Q1 2027, the relevant figure will be published September 2026.

Oregon coverage: who is in, who is out

ORS §90.323 applies to residential tenancies covered by the Oregon Residential Landlord and Tenant Act (ORS Chapter 90). The following classes of tenancies are exempt regardless of building age:

• Owner-occupied duplexes (ORS §90.323(2)(b)(B)): if the landlord occupies one unit in a two-unit residential structure as their primary residence, the other unit is exempt from SB 611 regardless of age. Duplexes where the landlord does not occupy either unit are covered once the building passes the 15-year threshold.
• Buildings under 15 years old: the rolling exemption removes all buildings with first CoC in the past 15 years from the cap’s reach. In 2026, buildings with first CoC issued after the 2026 notice date minus 15 years remain fully exempt.
• Subsidized housing: units subject to government-imposed rent restrictions (LIHTC, Section 8 project-based, state housing-authority regulatory agreements) are exempt because the applicable rent restriction already governs maximum rents.
• Manufactured/mobile-home park lots: mobile-home park lot rents are governed by Oregon’s separate manufactured-dwelling park law (ORS Chapter 90, Subchapter on Manufactured Dwellings) rather than by SB 611’s residential-tenancy cap.

Single-family homes and condominiums are generally covered by SB 611 once the building passes 15 years old — Oregon has no HHBO-notice SFR exemption comparable to California’s Costa-Hawkins §1954.52(a)(2)–(3). A landlord renting a free-standing house built in 2010 in Portland is fully subject to Oregon’s 9.5% cap once the building crosses its 15-year anniversary.

Oregon notice rules: 90 days, no exceptions

ORS §90.323(3) requires written notice of at least 90 days before the effective date of any rent increase, regardless of size. Oregon does not have California’s 30/90 split — even a 1% increase requires 90 days’ notice. This is the most stringent flat notice requirement among the four regimes and is a frequent source of surprise for California landlords who acquire Oregon property expecting the 30-day rule to apply.

Oregon has no prescribed government notice form requirement (unlike Washington, which mandates the Department of Commerce form). The landlord-authored written notice must include the amount of the increase, the new rent amount, and the effective date. Local Portland-area landlord associations publish suggested notice templates that also include ORS §90.323 citations, which aids documentation should a tenant contest the notice.

Oregon banking and vacancy decontrol

Oregon SB 611 uses the forfeit model for unused increases: the 9.5% annual cap is a ceiling on the current 12-month period only. A landlord who passes on a 2023 increase, a 2024 increase, and a 2025 increase cannot aggregate three years of capacity (approximately 9.5% × 3 = 28.5%) into a single 2026 increase of 28.5%. The maximum increase in calendar year 2026 is 9.5%, full stop. Skipped years are lost.

Oregon uses vacancy decontrol consistent with state property law: when a tenancy ends (voluntary move-out, non-payment eviction, lease expiration), the landlord may set the new rent at any amount for the incoming tenant. The cap then applies to future increases from whatever initial rent was set for the new tenancy.

Oregon just-cause: separate statute, same 2019 legislative moment

Oregon’s just-cause-for-eviction law (ORS §90.427, also enacted in SB 608 alongside the rent cap) requires landlords to have a stated statutory cause for terminating most month-to-month tenancies after the tenant has resided for longer than 12 months. The enumerated causes include non-payment of rent, material breach of the rental agreement, and owner-occupancy or demolition. Oregon’s just-cause law is structurally attached to the same 2019 legislative package as the rent cap but operates as a separate statute — a landlord cannot evict to circumvent the rent cap, but the cap and the eviction protection are not formally codependent in the way that AB 1482’s cap and just-cause provisions are (where both flow from the same statutory section and an AB 1482-covered unit gets both the cap and just-cause automatically).

Oregon penalties: ORS §90.323(5)

ORS §90.323(5) provides that a landlord who collects rent in excess of the maximum allowable increase is liable to the tenant for:

• Return of any excess rent collected,
• Damages in the amount of three months’ rent,
• Reasonable attorney fees and court costs.

Oregon’s three-months’-rent damages measure is the standard punitive element across all four regimes (Washington and California use the same measure). Montgomery County’s Bill 15-23 does not appear to specify a multiplied-damages formula in the same way, instead relying on Chapter 29’s general administrative enforcement by DHCA and civil suit recovery of excess rents.

Washington State HB 1217 (RCW §59.18.700): the 12-year window, 9.683% cap

Washington State enacted its first statewide rent-stabilization law on May 7, 2025, when Governor Bob Ferguson signed Engrossed House Bill 1217. HB 1217 was the result of years of advocacy following rapid rent increases in Seattle, Tacoma, and Spokane, and came into effect after several prior legislative sessions where rent-stabilization bills stalled or failed. The law is codified at RCW 59.18.700 through 59.18.770 for residential tenancies and at RCW 59.20.120 through 59.20.125 for manufactured and mobile-home park tenancies, which are governed by a separate 5% flat cap with no expiration.

HB 1217 introduces three structural features that distinguish it from the other three rolling-exemption regimes: a 12-year rolling window (the shortest), a categorical first-year protection (no increases at all in the first 12 months of any tenancy), and a residential-cap sunset on July 1, 2040. No other regime in this comparison has a sunset provision.

The 2026 Washington residential cap: 9.683%

Washington uses the BLS CPI-U series for the Seattle-Tacoma-Bellevue Metropolitan Statistical Area, measured June-to-June. For calendar year 2026, the Department of Commerce computed:

((364.344 − 354.824) / 354.824) × 100 + 7.000 = 9.683%

The Seattle-Tacoma-Bellevue CPI-U June 2024 to June 2025 measured approximately 2.683 percentage points of inflation. Adding the 7-point base additive yields 9.683%, which is below the 10% statutory ceiling (RCW §59.18.700(1)(a)). The cap is published by the Department of Commerce each July, shortly after the BLS releases the June CPI reading. For 2026 increases, the cap is 9.683% residential; 5% manufactured-home parks.

Washington’s cap is a calendar-year cap, not an anniversary-based cap. Any increase with an effective date between January 1, 2026 and December 31, 2026 is subject to the 9.683% ceiling, regardless of when the tenancy started. An increase with an effective date of March 1, 2027 — even if noticed in late 2026 — uses the CY 2027 cap (published by Commerce in July 2026), not the CY 2026 cap.

The 12-year rolling window and its coverage consequences

RCW §59.18.700(2)(d) exempts “a dwelling unit for which the first certificate of occupancy was issued less than 12 years before the proposed effective date of the rent increase.” Because HB 1217 only became effective in 2025, all buildings constructed before 2013 (more than 12 years before any 2025 increase effective date) were immediately covered on HB 1217’s effective date — they had already aged past the 12-year threshold by the time the law took effect.

The 12-year window is the shortest rolling window among the four regimes. Its practical consequence: in 2026, buildings with first CoC issued before approximately mid-2014 are covered by HB 1217. Buildings issued first CoC from mid-2014 through the present are still exempt and will graduate one by one as each building crosses its 12-year mark. By comparison, Oregon and California’s 15-year windows exempt all buildings built after approximately 2011, leaving a three-year cohort of 2011-2014 construction covered in Oregon and California but still exempt in Washington.

Washington’s categorical first-year protection: unique among the four regimes

RCW §59.18.700(1)(c) provides a categorical protection that no other rolling-exemption regime includes: a landlord may not increase the rent during the first 12 months after a tenancy begins, regardless of any other coverage analysis. The first-year protection is universal and applies regardless of building age, regardless of whether the building is exempt from the rolling-window cap, and regardless of the size of the proposed increase.

This first-year protection resets with every new tenancy. When a unit turns over — the prior tenant moves out, a new tenant signs a lease — the 12-month clock resets from the new tenancy’s start date. The new tenant has a categorical protection against any rent increase for their first 12 months.

After the first 12 months expire, the landlord may increase rent at most once per 12-month period (RCW §59.18.700(1)(b)) at up to the calendar-year cap (9.683% for 2026 residential). The once-per-12-months rule is separately stated from the first-year protection and continues throughout the tenancy.

Washington’s prescribed-notice-form requirement: a unique enforcement lever

RCW §59.18.700(3)(a) requires that the landlord use the rent-increase notice form prescribed by the Washington State Department of Commerce. The statute explicitly provides that a non-conforming notice — one that does not use the Commerce form or is missing required disclosures — is void: no increased rent may be collected under it, and the landlord remains subject to penalties for any increase that was purportedly implemented under it.

The Commerce form must include:

• Landlord and tenant identification; unit address.
• Current rent and proposed new rent.
• Effective date of the increase.
• The current calendar year’s maximum annual rent-increase percentage (published by Commerce) and a statement that the proposed increase does not exceed it, or a claim of exemption with specific citation to the applicable exemption provision.
• Tenant rights information, including remedies under RCW §59.18.730.

Oregon, Montgomery County, and California do not have a government-prescribed-form requirement. They allow landlord-authored notices provided the notice content satisfies the applicable statutory minimums. Washington’s prescribed-form requirement creates a binary compliance test: either the correct form was used or the notice is void. No other rolling-exemption regime uses this mechanism.

Washington vacancy decontrol and the 12-month reset

Like the other three regimes, Washington HB 1217 permits rent resets on legal vacancy. When a tenancy ends lawfully (voluntary move-out, lease expiration, eviction for non-payment or material breach), the landlord may set the new rent for the incoming tenant at any amount. The calendar-year cap then applies to subsequent increases from that reset baseline, and the first-year protection gives the new tenant a 12-month window before any increase is permitted.

Washington’s legislative record identifies vacancies caused by retaliatory eviction or unlawful discrimination as NOT qualifying for the vacancy-decontrol reset; in those cases the cap applies to the next tenancy from the prior tenant’s rent, and the displaced tenant may have additional remedies under RCW §59.18.240 (retaliation) or RCW §49.60 (Washington Law Against Discrimination).

Washington penalties: RCW §59.18.730

RCW §59.18.730 provides the most comprehensive penalty structure among the four regimes:

• Return of all excess rent collected above the maximum annual rent-increase percentage.
• Damages of up to three months’ unlawful rent (not a flat three months, but capped there).
• Reasonable attorney fees and costs.
• Civil penalties of up to $7,500 per violation — unique among the four regimes; none of the others include a civil-penalty element separate from damages.

Washington also grants the Office of the Attorney General parens patriae enforcement authority, allowing the AG to pursue civil penalties on behalf of tenants as a class, not merely individual-plaintiff litigation. No other rolling-exemption regime in this comparison includes state-AG enforcement authority of this scope.

The 2040 sunset: the regime’s most distinctive feature

RCW §59.18.770 provides that most residential provisions of HB 1217 — including the annual cap, the 90-day notice requirement, the once-per-12-months rule, and the Department of Commerce prescribed-form requirement — sunset on July 1, 2040. The manufactured/mobile-home park cap at RCW §59.20.120 (flat 5%) has no expiration.

The 2040 sunset was a deliberate legislative compromise. Housing-construction industry opponents of HB 1217 argued that permanent rent stabilization would reduce housing supply; the Legislature responded by building in a 15-year review horizon that requires the Legislature to affirmatively reauthorize the law before July 1, 2040 if it wishes the residential cap to continue. Without reauthorization, the residential cap dissolves on that date. Washington landlords and tenant advocates should treat the 2038-2039 legislative sessions as the critical renewal window.

Montgomery County Bill 15-23 (Chapter 29 Article VII): the 23-year window, 5.8% VRGA

Montgomery County, Maryland enacted Bill 15-23 on July 25, 2023 (effective July 23, 2024), adding Article VII to Chapter 29 of the Montgomery County Code and establishing the county’s first modern rent-stabilization regime. Administered by the Department of Housing and Community Affairs (DHCA) through the Office of Landlord-Tenant Affairs, Bill 15-23 is structurally distinct from the three other regimes in this comparison in three ways: it uses the longest rolling window (23 years), the smallest base additive (CPI + 3%), and the tightest hard ceiling (6%).

Montgomery County is an unusual jurisdiction for rent stabilization — it is a wealthy suburban county in the Washington, D.C. metropolitan area, home to federal agency headquarters, biomedical research campuses, and some of the highest median household incomes in the United States. The justification for Bill 15-23 was the rapid post-pandemic rent surge that saw Montgomery County asking rents increase 15-20% from 2021 to 2023, driven in part by D.C. overflow demand and transit-oriented development. The 23-year rolling window was chosen to provide a long new-construction incentive while still reaching the large stock of apartment buildings constructed in the 1970s, 1980s, 1990s, and 2000s.

The 2026 Montgomery County cap: 5.8% through June 30, 2026

Montgomery County’s cap is expressed as a Voluntary Rent Guideline Allowance (VRGA), published by DHCA each mid-June for the following Rent Year (July 1 through June 30). The formula is:

min(6%, CPI-U Washington-Arlington-Alexandria MSA May-to-May + 3%)

For Rent Year 2025-2026 (July 1, 2025 through June 30, 2026), DHCA measured the Washington-Arlington-Alexandria MSA CPI-U May 2024 to May 2025 at approximately 2.8%, producing a formula result of 2.8% + 3% = 5.8% — below the 6% ceiling. The VRGA is 5.8% through June 30, 2026.

For increases with effective dates on or after July 1, 2026, the RY 2026-2027 VRGA applies, to be published by DHCA on or about June 15, 2026 using the May 2026 CPI reading. Absent final publication, landlords should assume the 6.0% ceiling and recompute once DHCA publishes. The key point: the effective date — not the notice date — determines which VRGA applies in Montgomery County.

The 23-year window: broadest coverage among the four regimes

The 23-year rolling window is the longest in this comparison and means that in 2026, buildings with first U&O permit issued before approximately 2003 are covered by Bill 15-23. By the time Bill 15-23 took effect on July 23, 2024, any building with a first U&O permit before July 23, 2001 was immediately covered.

The housing-stock consequence is substantial. Montgomery County’s apartment construction history includes major waves of garden-apartment and mid-rise construction in the 1970s (Rockville Pike corridor), 1980s (Bethesda-Chevy Chase), 1990s (Silver Spring, Gaithersburg), and early 2000s (transit-oriented development along the Red Line). All of this pre-2001 construction was covered immediately on Bill 15-23’s July 2024 effective date, and buildings from the 2001-2003 window graduate one by one through 2024-2026. By 2027, buildings from the mid-2000s construction boom will begin graduating. By 2040, all apartments built before 2017 will be covered — a remarkably comprehensive share of the county’s multifamily rental stock.

Compare this to California AB 1482 and Oregon SB 611, each with 15-year windows: those regimes currently exempt all buildings built after approximately 2011 (a post-recession construction cohort). Montgomery County’s 23-year window captures the 2001-2011 cohort that Oregon and California still exempt — including a large share of suburban mid-rise construction built during the 2003-2007 U.S. housing boom.

Montgomery County notice, frequency, and banking

Bill 15-23 requires landlord-authored written notice of at least 90 days before the effective date of any covered rent increase (Chapter 29, Article VII). Maryland Real Property §8-208 separately requires 60 days’ notice for month-to-month tenancies, but the stricter 90-day county rule prevails for rent-stabilized units.

The notice must include: landlord name and contact information; tenant name and unit address; current and new rent amounts; effective date; the Rent Year and VRGA being applied; and a statement of compliance with Chapter 29 Article VII. Montgomery County does not require a government-prescribed notice form (unlike Washington State), but DHCA provides guidance on suggested notice content.

Article VII bars more than one rent increase per rolling 12-month period on any single unit, regardless of tenant turnover within that 12 months. If a landlord served a notice with a November 1, 2025 effective date, the next increase on the same unit cannot take effect until November 1, 2026 at the earliest.

Like the other three regimes, Montgomery County uses the forfeit model: unused VRGA capacity does not roll forward. A landlord who skipped a 5.8% increase for RY 2025-2026 cannot add it to the RY 2026-2027 cap in a combined notice.

Montgomery County vacancy treatment

Chapter 29 Article VII permits rent reset on legal vacancy: when a tenancy ends (voluntary move-out, non-payment eviction, lease non-renewal), the landlord may set the new rent at market for the incoming tenant. The VRGA cap then applies to subsequent increases from the new baseline rent. Vacancies caused by retaliatory or discriminatory conduct do not qualify for the reset — the VRGA applies to the next tenancy from the displaced tenant’s rent.

Montgomery County’s vacancy-decontrol provision is broadly similar to Oregon’s and California’s, but differs from Washington’s unique first-year protection: in Washington, even after a legal vacancy reset, the incoming tenant’s first 12 months are categorically protected. Montgomery County has no equivalent first-year protection.

Montgomery County enforcement: DHCA administrative track plus civil suit

The DHCA Office of Landlord-Tenant Affairs serves as both regulator and dispute-resolution body for Bill 15-23 complaints. A tenant who believes their landlord has exceeded the VRGA may file an administrative complaint with DHCA, which may investigate and, if a violation is found, issue an order requiring the landlord to refund excess rents with interest. DHCA may also refer violations to the County Attorney for civil enforcement.

Tenants may alternatively (or additionally) pursue a civil suit in the Montgomery County Circuit Court or District Court for recovery of excess rents and such other remedies as the court may award. The absence of a statutory three-months’-rent damages multiplier in Bill 15-23 (unlike Oregon ORS §90.323(5) and Washington RCW §59.18.730) means the recovery ceiling in a Montgomery County civil suit is more dependent on actual damages and court discretion than in the Pacific Northwest regimes.

California AB 1482 (Cal. Civ. Code §1947.12): the 15-year window, ~8% cap, the comparison anchor

California’s Tenant Protection Act of 2019 (AB 1482, effective January 1, 2020) established the statewide rent-cap framework that covers California residential tenancies not governed by a more protective local rent-control ordinance. It uses the same 15-year rolling window as Oregon but a different cap formula: 5% plus the applicable regional CPI, with a 10% hard ceiling under Cal. Civ. Code §1947.12(a).

California’s 5% base additive is lower than Oregon’s 7% and Washington’s 7% but higher than Montgomery County’s 3% relative to CPI. In a year like 2026 when California MSA CPIs run approximately 2.5-3.0%, the formula produces caps of approximately 7.5-8.0%. Because California uses two different MSA CPI indices depending on county — the Los Angeles-Long Beach-Anaheim MSA for most of Southern California and the San Francisco-Oakland-Hayward MSA for the Bay Area and Northern California — the AB 1482 cap in 2026 is approximately 8.0% for LA-MSA counties and approximately 8.0% for SF-MSA counties (with both running at roughly similar CPI levels for 2026).

AB 1482 in context: the two-tier California structure

AB 1482 is structurally unique among the four regimes because it operates as a statewide floor that applies only when a more protective local ordinance does not. Cal. Civ. Code §1947.12(h)(2) provides that AB 1482 does not apply to units governed by a local ordinance providing equal or greater tenant protections than the section. This means:

• A unit covered by the LA RSO (Los Angeles Municipal Code §151) gets the LA RSO cap (approximately 3% for 2026 under the Council-published rate) — not the AB 1482 ~8% cap. AB 1482 is displaced.
• A unit in a San Francisco building built after 1979 (post-Costa-Hawkins in terms of SF local RSO) gets AB 1482 at ~8%, because the SF Rent Ordinance does not cover post-1979 buildings and AB 1482 fills the gap.
• A unit in a city with no local RSO — Glendale, Burbank, Irvine, most Orange County cities, most Central Valley cities — gets AB 1482 at ~8% for 2026.

Oregon, Washington, and Montgomery County do not have this two-tier structure. In each of those jurisdictions, the rolling-exemption statute is the sole applicable cap law (subject to local just-cause rules in Seattle and Tukwila in Washington, but with no competing cap overlay at the local level that would displace or supplement the state cap).

The AB 1482 rolling exemption and SFR carve-outs

Cal. Civ. Code §1947.12(d) provides two exemption categories beyond the rolling new-construction window:

• Single-family homes and condominiums (§1947.12(d)(2)–(3), following Costa-Hawkins §1954.52(a)(3)): a single-family home or condo is exempt from AB 1482 if the landlord serves a statutory notice at the commencement of the tenancy informing the tenant of the SFR exemption. This HHBO-notice exemption does not exist in Oregon, Washington, or Montgomery County. Oregon SB 611, Washington HB 1217, and Montgomery County Bill 15-23 all cover eligible single-family rentals once the building passes the rolling window, without any notice-triggered carve-out available to the landlord.
• Owner-occupied duplexes: California follows the same owner-occupied-duplex exemption as Oregon: if the landlord occupies one unit of a duplex as their principal residence, the other unit is exempt from AB 1482. This exemption does not depend on the building’s age.

California’s 30/90 notice split: unique among the four regimes

Cal. Civ. Code §827(b) provides:

• For rent increases of 10% or less above the lowest rent charged in the preceding 12 months: at least 30 days’ written notice.
• For increases of more than 10%: at least 90 days’ written notice.

Because AB 1482’s cap is itself the lower of 10% or 5% + CPI, and because in 2026 the applicable caps resolve to approximately 8%, all AB 1482 increases in 2026 are 10% or less and thus eligible for the 30-day notice period. In practice, a landlord implementing the full AB 1482 ~8% increase needs only 30 days’ notice — a meaningful operational advantage over Oregon, Washington, and Montgomery County, all of which require 90 days regardless of size.

California’s 30-day option is the product of §827(b)’s original drafting for month-to-month tenancies. Oregon, Washington, and Montgomery County all adopted uniform 90-day rules when enacting their statewide caps, choosing tenant-protective clarity over the California split rule.

AB 1482 no banking, vacancy decontrol, and just-cause attachment

California AB 1482 uses the forfeit model (no banking), vacancy decontrol (rent resets on legal vacancy), and attaches just-cause-for-eviction requirements automatically to AB 1482-covered units under Cal. Civ. Code §1946.2. This just-cause attachment is more tightly integrated than Oregon’s separate SB 608 just-cause statute: a California unit covered by AB 1482 automatically gets both the cap and the just-cause protection as a bundle, and the SFR HHBO exemption from the cap simultaneously exempts the unit from just-cause as well. Oregon’s just-cause protections are in a separate statute and apply independently of whether the unit is cap-covered.

Formula comparison: 7% + CPI (Oregon, Washington), 5% + CPI (California), CPI + 3% (Montgomery County)

All four rolling-exemption regimes use additive CPI formulas — a base percentage plus an annual CPI measurement — with a hard ceiling. But the formulas differ in structure in a way that produces meaningfully different outcomes across the CPI range:

A structural pattern emerges from that table: in 2026, all four regimes’ formula results fall below their respective hard ceilings. The hard ceilings bind only when inflation is high enough to push the formula past them. For the 10% ceilings (Oregon and Washington), that requires CPI to exceed 3%: if CPI runs 3.1%, the formula results are 10.1%, and the ceiling caps the effective rate at 10%. For Montgomery County’s 6% ceiling, the ceiling binds when CPI exceeds 3%: 3.1% + 3% = 6.1%, capped to 6%. California’s 10% ceiling binds when CPI exceeds 5%: 5% + 5.1% = 10.1%, capped to 10%.

This means Montgomery County’s hard ceiling is the most likely to bind among the four regimes. Its 6% ceiling is breached whenever the Washington-Arlington-Alexandria MSA CPI exceeds 3% — a threshold reached in 2021, 2022, 2023, and 2024 during the post-pandemic inflation surge. A landlord in the DC area whose building graduated during those high-CPI years received a VRGA capped at 6% while the formula (CPI + 3%) would have produced 8-9% if uncapped. Oregon and Washington, by contrast, maintained uncapped access to the formula-result cap (12-13% in high-CPI years) before eventually implementing the 10% explicit ceilings.

Why the base additives differ: the political equilibria of each regime

The base additive — the percentage above CPI that the cap grants — reflects each jurisdiction’s political negotiation between tenant-protective and landlord-protective forces at the time of enactment.

Oregon’s 7% base was set in 2019 in the context of no prior statewide cap. The legislature’s goal was to establish a meaningful cap on runaway rent increases while leaving room for landlords to recover operating cost increases that might exceed CPI (property insurance, maintenance, property tax increases driven by assessed-value appreciation). A 7% base means that even in a zero-inflation year, the cap allows 7% increases — a substantial landlord margin that attracted bipartisan support for Oregon SB 608.

Washington’s 7% base (identical to Oregon’s) reflects the influence of Oregon’s legislative history in HB 1217’s drafting. Washington advocates and legislators studied Oregon’s SB 608/611 record extensively, and the decision to copy Oregon’s formula structure while using a narrower CPI anchor (Seattle MSA vs. the broader West Region) reflects Washington’s higher base rents and tighter housing market.

California’s 5% base (two points lower than Oregon) reflects that AB 1482 was negotiated in a state that already had a dense patchwork of local RSOs providing much lower caps (LA RSO at 3%, Berkeley at 1%, Oakland at 1.7%). The 5% base was set to be clearly above the existing local-RSO caps (avoiding the appearance of displacing them) while still capping the otherwise-unregulated middle-market rental housing in cities without local RSOs.

Montgomery County’s 3% base is the smallest of the four, producing the lowest cap. It reflects both the county’s politically moderate character and the fact that 3% + DC-area CPI was calibrated to be the minimum landlord buffer that could survive the county’s real-estate industry opposition. The 6% hard ceiling further constrains the formula’s reach in high-CPI years.

Window-length consequences: which housing stock is covered in 2026 under each regime?

The window length — 12, 15, 15, or 23 years — determines which cohorts of apartment construction are currently exempt versus covered under each regime. The comparison below shows the approximate construction-year boundary for each regime in 2026:

The window-length difference has a substantial consequence for which vintage of construction is protected in each jurisdiction.

Washington’s 12-year window exempts the largest share of recent construction among the four regimes. All buildings issued first CoC from mid-2014 through 2026 are exempt from HB 1217 — a 12-year cohort spanning the post-recession construction recovery, the 2015-2019 apartment boom, and the post-COVID construction surge. Landlords of Seattle and Tacoma apartments built between 2014 and 2022 face no HB 1217 cap constraint and may raise rents without restriction (subject only to local just-cause rules in Seattle and Tukwila).

Oregon and California’s shared 15-year window covers three more construction years than Washington — the 2011-2014 cohort. This cohort represents the early stages of the post-2008-recession apartment construction recovery: buildings financed during a period of cheap capital and low construction cost but now 12-15 years old and in many cases seeing first major maintenance cycles. In Portland and San Francisco suburbs, this cohort includes a meaningful volume of apartment buildings that were new-construction luxury units in 2012-2014 and have now filtered down toward middle-market rents.

Montgomery County’s 23-year window covers by far the broadest swath of housing stock. Buildings with first U&O permit before 2003 are covered — this includes virtually all of Montgomery County’s garden-apartment stock from the 1970s, 1980s, and 1990s construction waves, plus the county’s early-2000s transit-oriented development. The 2003-2011 cohort (which Oregon and California still exempt) is covered in Montgomery County. The net result: Bill 15-23 reaches a materially larger percentage of the county’s total rental units than the 15-year regimes reach in Oregon and California.

There is a direct political-economy tradeoff at work in this comparison: regimes with longer windows cover more housing stock (better for tenants seeking protection) but require a lower cap to attract political support (less favorable for landlords). Regimes with shorter windows cover less housing stock but can sustain higher caps because the new-construction incentive is less compromised. Montgomery County’s 23-year window + 5.8% cap illustrates one end of this tradeoff; Washington’s 12-year window + 9.683% cap illustrates the other.

Notice-period mechanics, vacancy decontrol, and the Washington first-year protection

Across the four regimes, landlords face three categories of timing rules that interact with the cap: the notice period before an increase takes effect, the frequency of increases, and the treatment of new tenancies.

Notice periods: the California 30/90 split vs. universal 90-day rules

California is the only regime with a split notice requirement. Cal. Civ. Code §827(b) requires 30 days for increases at or below 10% of the lowest rent in the preceding 12 months, and 90 days for increases above 10%. In practice, AB 1482’s cap of ~8% means all normal AB 1482 increases qualify for the shorter 30-day period.

Oregon (ORS §90.323(3)), Washington (RCW §59.18.700(3)(a)), and Montgomery County (Chapter 29 Article VII) each require 90 days for all increases, regardless of size. A 1% increase in Portland requires 90 days. A 1% increase in Seattle requires 90 days and the prescribed Commerce form. A 1% increase in Rockville requires 90 days of landlord-authored written notice. This universal 90-day rule is the tenant-protective choice all three non-California regimes made; it eliminates a category of landlord errors where a landlord underestimates the applicable notice period.

Frequency: once per 12 months in all four regimes

All four regimes cap increases at once per rolling 12-month period per unit: Oregon (ORS §90.323 and administrative interpretation), Washington (RCW §59.18.700(1)(b)), Montgomery County (Chapter 29 Article VII), and California (Cal. Civ. Code §1947.12 and AB 1482 implementing guidance). A landlord cannot split an annual allowance into two increases of 4.75% each (for Oregon or Washington) served six months apart. The full annual allowance is permitted once per 12-month period.

Vacancy decontrol: all four allow market reset

All four regimes permit vacancy decontrol: when a covered tenancy ends through a legal mechanism (voluntary move-out, expiration without renewal, eviction for cause), the landlord may reset the rent for the incoming tenant at market. From that new baseline, the regime’s cap governs future increases.

In practical terms, vacancy decontrol means the cap governs only the trajectory of a continuing tenancy, not the level at which a new tenancy begins. A long-term tenant who has received 9.5% Oregon increases for five years while market rents in their Portland neighborhood have grown 15% annually is likely paying below-market rent. When they vacate, the landlord resets to market and the new tenant starts a new 12-month clock at the new baseline. This dynamic — cap-limited trajectories within a tenancy, market-level resets on vacancy — characterizes all four regimes.

Washington’s first-year protection: a categorical floor

Washington is the only regime that layers a categorical first-year protection on top of vacancy decontrol. After a legal vacancy reset, the new tenant has a full 12 months free of any rent increase — even if the landlord serves a 90-day notice within the first two months of the new tenancy. The increase cannot take effect until at least 12 months have elapsed since the new tenancy began.

The first-year protection is not conditioned on building age: it applies whether the building is 3 years old (and exempt from the cap itself) or 20 years old (and covered by the cap). The categorical protection thus creates a two-layer rule for covered buildings: no increase at all in year 1, up to 9.683% per year from year 2 onward.

Oregon, California, and Montgomery County have no comparable first-year protection. A landlord may serve a 90-day notice on day 1 of a new tenancy in those jurisdictions (with the effective date falling 90 days later), and the increase is valid provided it is within the applicable cap.

Penalty comparison and enforcement geography

All four regimes impose civil penalties for excess-rent collection, but the structure and ceiling of those penalties differ materially. The following summarizes the penalty cascade for each regime:

Washington’s penalty structure is the strongest among the four regimes. The $7,500 per-violation civil penalty — which the Attorney General can pursue on behalf of a class of tenants without individual plaintiff action — creates enforcement pressure that is absent from the other three regimes. A landlord who overcharges 20 tenants by $200 each per month for a year faces: $48,000 in excess-rent returns, potential $720,000 in per-violation penalties ($7,500 × 20 violations × 12 months if each month is a separate violation), plus attorney fees. Oregon’s three-months’-rent statutory damages measure is significant but does not reach the Washington penalty ceiling.

Montgomery County’s enforcement depends more on administrative action by DHCA than on civil litigation, reflecting the county’s preference for administrative resolution over court proceedings. DHCA’s ability to investigate and order refunds provides a lower-barrier enforcement mechanism for tenants who cannot access attorneys, but the absence of a statutory damages multiplier reduces the deterrence effect compared to Oregon’s and Washington’s multiplied-damages provisions.

California’s AB 1482 penalty provisions are modest at the state level, partly because the more heavily enforced California rent-cap violations tend to arise under local RSOs (which often have their own penalty structures) rather than under AB 1482’s statewide backstop. LA RSO violations, for example, are subject to LAHD enforcement and can result in administrative fines separate from any civil action.

Banking and the forfeit model across all four regimes: a three-year scenario

All four rolling-exemption regimes share one key structural feature: none permits banking of unused annual increases. The cap is a per-12-month-period ceiling only. Skipping an annual increase does not accumulate a credit for future use.

Consider a landlord with a covered $2,000/month unit in all four jurisdictions, who skips increases in 2023, 2024, and 2025 (three consecutive years at zero increase), then serves notice in 2026:

The forfeit model is identical across all four regimes: a landlord who skips increases is permanently capped in the current year at the current-year ceiling, without any catch-up mechanism. This is in sharp contrast to California local RSOs like Berkeley BMC §13.76.110(C) (unlimited accumulation — a landlord who skipped 2023, 2024, and 2025 can collect approximately 3.0% in one 2026 notice without a ceiling) and Mountain View CSFRA §1707(c) (10%-per-notice ceiling — same landlord could collect up to 10% in one 2026 notice including all three years’ banked balances). The rolling-exemption regimes studied in this post uniformly reject banking, keeping the cap structure simple but providing landlords no path to recover skipped-year increases from long-term tenants.

What changes on graduation day: four-way comparison

Graduation day — the moment a building crosses its rolling-window threshold and becomes subject to the cap for the first time — triggers different bundles of obligations in each regime:

Oregon (graduation day): the building becomes subject to ORS §90.323’s 9.5% annual cap (for 2026 increases noticed after the graduation date). The landlord may not serve an increase notice above the cap from that point forward. Oregon’s just-cause eviction protections (ORS §90.427) apply separately and are not triggered by graduation day — they apply based on tenancy duration regardless of whether the building is cap-covered. There is no separate cap registration requirement in Oregon, no annual filing, and no rent board to notify. Graduation is self-executing: the cap attaches the moment the building crosses the threshold, and enforcement is through private tenant litigation under ORS §90.323(5) if the landlord overcharges.

Washington (graduation day): the building becomes subject to the 9.683% annual calendar-year cap (for 2026). Crucially, for a building that graduates mid-year, the cap applies only to increases with effective dates on or after the graduation date (because the trigger is the effective date, not the notice date). A landlord who served a notice in March 2026 with a June 2026 effective date for a building graduating in August 2026 does not have the cap apply to that notice — the effective date is before graduation. Subsequent notices with effective dates after August 2026 are fully capped. Additionally, once covered, any increase notice must use the Department of Commerce prescribed form. This is the most significant administrative obligation created on graduation day: not just the cap attaches, but the notice mechanics change from landlord-authored to the prescribed form.

Montgomery County (graduation day): the building becomes subject to the VRGA (5.8% for increases effective through June 30, 2026; pending RY 2026-27 figure for increases effective July 1, 2026 onward). The cap attaches as of the graduation date (which here is the first day the proposed effective date falls at least 23 years after the U&O permit date). There is no registration requirement on graduation day specific to Bill 15-23, but DHCA recommends landlords maintain documentation of the U&O permit date as evidence of exemption status during any compliance dispute.

California (graduation day): the building becomes subject to AB 1482’s ~8% cap and to the Cal. Civ. Code §1946.2 just-cause-for-eviction requirements simultaneously, because both protections are bundled in the same statute. Additionally, if the landlord has not previously served a Cal. Civ. Code §1946.2(e) notice informing the tenant of the just-cause protections, DHCA recommends doing so promptly after graduation. The SFR HHBO notice that exempts single-family homes from AB 1482 must have been served at the commencement of the tenancy to be valid — it cannot be retroactively served on graduation day to avoid the newly attached cap.

The most operationally complex graduation among the four regimes is Washington’s, because the prescribed-form requirement means the landlord must start using the Department of Commerce form for all subsequent notices once the building graduates. A landlord who continues using a self-drafted notice form after graduation is using a void notice and cannot collect any increased rent under it. Oregon, Montgomery County, and California allow self-drafted notices throughout, creating no form-compliance transition requirement on graduation day.

FAQ

What is the difference between a rolling first-CoC exemption and a permanent post-construction carve-out like Costa-Hawkins?

A permanent carve-out fixes a single calendar date: every building with a first certificate of occupancy issued after that date is permanently and unconditionally exempt from rent control, forever. California’s Costa-Hawkins Rental Housing Act (Cal. Civ. Code §1954.52(a)(1)) is the canonical example — any building with first CoC on or after February 1, 1995 is exempt from local rent control in perpetuity; that exemption never lapses regardless of how old the building becomes.

A rolling exemption ties the exemption to each building individually based on its own CoC date. Under Oregon SB 611 (ORS §90.323(2)(a)), the 15-year rolling exemption means: a building issued first CoC in May 2010 was exempt in 2019 (9 years old), remained exempt in 2024 (14 years old), and became permanently covered in May 2025 (15-year anniversary). Coverage, once attached on graduation day, does not lapse. The practical consequence over time: rolling exemptions eventually cover all housing stock as every building ages past the window, while a permanent carve-out like Costa-Hawkins creates a permanent and expanding universe of exempt buildings as new construction continues.

My Oregon duplex received its first certificate of occupancy in June 2011 — is it covered by Oregon SB 611 today?

Yes, provided you do not personally occupy the other unit. Oregon SB 611 (ORS §90.323(2)(a)) exempts units whose first CoC was issued less than 15 years before the date of the notice of the rent increase. A building with first CoC in June 2011 crossed its 15-year threshold in June 2026. Any notice served on or after that date is subject to the 9.5% cap for 2026. The duplex exemption (ORS §90.323(2)(b)(B)) applies if you live in one unit as your primary residence — in that case the second unit remains exempt from the cap regardless of age.

Because Oregon requires 90 days’ notice for all increases, a notice served in early September 2026 with an effective date of December 1, 2026 would be a valid SB 611-covered notice, with the 9.5% ceiling applying to the December 2026 increase.

Why does Washington’s HB 1217 cap resolve to 9.683% for 2026 while Oregon’s SB 611 resolves to 9.5%, when both use the same “7% + CPI capped at 10%” formula?

Both regimes share the same algebraic structure — min(7% + CPI, 10%) — but use different CPI series over different geographies. Oregon measures the BLS CPI-U West Region (a broad multi-state composite); Washington measures the BLS CPI-U Seattle-Tacoma-Bellevue MSA (a single metro area), both annually. For 2026: Oregon’s West-Region CPI read approximately 2.5%, producing 9.5%. Washington’s Seattle MSA CPI measured June 2024–June 2025 read approximately 2.683%, producing 9.683%. Seattle’s housing cost inflation ran approximately 0.18 points higher than the broader West-Region composite in that period. In years when Seattle MSA CPI underperforms the West Region, Washington’s cap would be lower than Oregon’s despite the identical formula structure.

Is a Montgomery County rental property built in 2003 covered by Bill 15-23 as of 2026?

It depends on the specific U&O permit date. Any building with first U&O permit issued before the effective date minus 23 years is covered. For a proposed increase with an effective date of March 1, 2026: the trigger date is March 1, 2003. A building permitted before March 1, 2003 is covered. A building permitted on or after March 1, 2003 is still exempt for that specific increase. A building permitted January 15, 2003 graduated on January 15, 2026 and is covered. A building permitted September 1, 2003 will not graduate until September 1, 2026. The 2003 vintage is therefore transitional in 2026, with the first half of 2003 covered and the second half still exempt for most of the year.

Does California AB 1482 apply to a building that also has a local RSO like the LA RSO or Berkeley BMC §13.76?

No. Cal. Civ. Code §1947.12(h)(2) displaces AB 1482 for units covered by a local ordinance providing equal or greater tenant protections. If the LA RSO (LAMC §151) governs a unit — pre-October 1, 1978 first CoC, in the City of Los Angeles — the applicable cap is the LA RSO rate (approximately 3% for 2026 under the Council-published rate), not AB 1482’s ~8%. Berkeley BMC §13.76 similarly displaces AB 1482 for Berkeley units with first CoC before February 1, 1995. AB 1482 functions as the statewide floor for all California residential tenancies that are not covered by a more protective local overlay — which is the majority of California’s rental units, given the large number of cities with no local RSO. Oregon, Washington, and Montgomery County have no equivalent two-tier structure; the state/county cap is the sole applicable regime.

If I skipped three years of increases in Oregon or Washington, can I bank them and take all three years at once in year four?

No. Neither Oregon SB 611 nor Washington HB 1217 permits banking of unused annual increases. Oregon’s cap is a per-12-month-period ceiling under ORS §90.323; Washington’s cap is a per-calendar-year ceiling under RCW §59.18.700. Unused capacity in any prior period is forfeited permanently. The maximum increase in 2026 is 9.5% (Oregon) or 9.683% (Washington) regardless of how many prior-year increases were skipped. Montgomery County and California AB 1482 operate identically — all four rolling-exemption regimes use the forfeit model. This is in contrast to California local RSOs like Berkeley (unlimited accumulation) and Mountain View (10% per-notice ceiling with carryforward), which permit banking.

What happens to Washington State tenants’ rent protection when the HB 1217 residential cap sunsets in 2040?

Under RCW §59.18.770, the residential annual cap, the 90-day notice form requirement, and the once-per-12-months rule sunset on July 1, 2040. Absent legislative reauthorization, Washington residential landlords may raise rents without the cap on that date. Three protections survive the sunset: (1) The 5% cap on manufactured/mobile-home park spaces (RCW §59.20.120) has no expiration. (2) Local government rent-control authority in Seattle and Tukwila is unaffected. (3) Fair Housing Act protections against discriminatory rent increases continue. The 2040 sunset was a deliberate legislative compromise — housing-industry opponents of HB 1217 secured the sunset as a condition of passage. Washington landlords and tenant advocates should treat the 2038-2039 legislative sessions as the critical renewal window. Oregon, California, and Montgomery County have no sunset provisions — their rolling-exemption caps are permanent statutes.

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