Snohomish County Rent Increase Laws: Caps, Notices, and Exemptions

Snohomish County rent increase laws now follow a single statewide rule under Washington’s HB 1217: a landlord can raise rent no more than 7% plus the Consumer Price Index or 10%, whichever is lower, in any 12-month period, and must give at least 90 days’ written notice before the new rate takes effect.¹² For the period from January 1 through December 31, 2026, the maximum allowable increase is 9.683%.

How the Annual Cap Works

Before HB 1217 took effect in May 2025, Washington landlords could raise rent to any amount they chose as long as they gave proper notice. The new law, codified at RCW 59.18.700, changes that. The Department of Commerce recalculates the cap each year using the June-to-June CPI change for the Seattle area published by the Bureau of Labor Statistics, and the 2026 figure comes out to 9.683%.¹

The cap runs on a rolling 12-month window, not a calendar year. A landlord who bumps your rent 5% in March cannot add another 5% in September, because the combined increase inside that window would blow past the cap.¹

On top of the cap, no rent increase of any kind is allowed during the first 12 months of a tenancy. That holds whether you signed a one-year lease or started month-to-month, and it holds even if a short lease converts to month-to-month before the year is up.¹

Which Properties Are Exempt

Not every rental in Snohomish County is covered. RCW 59.18.710 carves out several categories:

New construction, for the building’s first 12 years.
Owner-occupied duplexes, triplexes, and fourplexes where the owner lives in one of the units.
Public housing authority properties and designated low-income developments, which follow their own program rules.
Manufactured and mobile home lot rents, which are capped separately at 5% per year with no expiration.

If your landlord claims an exemption, you can check it. The new-construction exemption, for example, is tied to the building’s certificate of occupancy date. Landlords who raise rent above the cap on a non-exempt property face penalties of up to $7,500 per violation, enforceable by the state Attorney General.³

The 90-Day Written Notice Rule

Every landlord in Snohomish County must give at least 90 days’ written notice before a rent increase takes effect. This covers both month-to-month tenancies and fixed-term leases coming up for renewal.² The Washington Attorney General’s office confirms the same requirement.⁴

The 90-day clock starts when you receive proper notice, not when the landlord writes or mails it. An increase also cannot take effect before the current rental period or lease term ends, even if 90 days have otherwise passed. If a landlord hands you a notice with only 75 days left on your lease, you keep paying the old rate until 90 full days have run from the date you were served.

There is one narrow exception: in subsidized housing where rent is based on household income, only 30 days’ notice is required before a rent adjustment.²

Notice has to be written. Email and text messages don’t satisfy Washington’s written notice requirements for rent increases, so if the only thing your landlord sent was an email, the increase hasn’t been properly served. In practice, landlords use personal delivery, substitute service on someone of suitable age at the residence, or posting on the property combined with mailing a copy. Keep whatever notice you receive and note the date you got it, because that date is what matters if the timing is later disputed.

Mid-Lease Increases

A landlord cannot raise your rent in the middle of a fixed-term lease unless the lease itself contains a clause allowing mid-term adjustments. Without that clause, your rent is locked for the duration of the agreement. This rule predates HB 1217 and remains unchanged.²

When a fixed-term lease is about to expire, the landlord can propose a higher rate for the renewal period. The same rules then apply: 90 days’ written notice, and the increase cannot exceed the annual cap unless the property is exempt.

Retaliatory Rent Increases

Washington law presumes a rent increase is retaliatory if it comes within 90 days of a tenant exercising a legal right. That includes filing a complaint with a building inspector, reporting a health code violation, or asserting any right under the state’s landlord-tenant act or a local ordinance.⁵

The burden of proof flips. If you reported a code violation on June 1 and your landlord issued a rent increase notice on July 15, the law assumes the increase is punishment, and the landlord has to prove in court that it was driven by legitimate business reasons. The presumption does not apply if the increase is part of a uniform raise across the entire building or mobile home park.⁵

A tenant who proves retaliation can recover court costs and reasonable attorney’s fees.⁶

Discrimination and Source of Income

A rent increase that looks neutral on paper can still violate the law if it targets tenants based on a protected characteristic. The federal Fair Housing Act prohibits discrimination in any housing-related decision based on race, color, national origin, religion, sex, familial status, or disability.⁷ A pattern of larger increases on units occupied by families with children or tenants of a particular background can support a discrimination claim even without a written admission of bias.

Washington adds a protection most states lack. Under RCW 59.18.255, landlords cannot discriminate against tenants based on their source of income, which includes housing vouchers, public assistance, veterans benefits, Social Security, and other government or nonprofit programs.⁸ A Snohomish County landlord who selectively raises rent on voucher-holding tenants while leaving comparable units unchanged could face a source-of-income claim.

What to Do If Your Landlord Exceeds the Cap

If your landlord raises rent above the legal maximum without qualifying for an exemption, you have two paths. You can notify the landlord of the error and give them a chance to correct the increase to a lawful amount. If they don’t, you can terminate your lease with 20 days’ written notice. You are not required to accept an illegal increase or keep living under those terms.

The Washington Attorney General’s office can also investigate and bring enforcement actions. Penalties can reach $7,500 per violation.³ A landlord running multiple non-exempt properties who systematically exceeds the cap faces compounding liability across every affected unit.

For a retaliatory increase, the remedy is separate: if a court or arbitrator finds the increase violated RCW 59.18.240, you recover court costs and reasonable attorney’s fees.⁶ Document everything in writing, especially repair requests and any complaints you make to the landlord or an agency, so you have a record if the dispute escalates.

Local Rent Control Is Preempted

Snohomish County and the cities within it cannot pass their own rent control ordinances. RCW 35.21.830 bars cities from regulating rent amounts for private residential properties, and RCW 36.01.130 extends the same prohibition to counties.⁹ The Attorney General’s office has confirmed that this preemption blocks both cities and counties from imposing any form of rent regulation beyond what the state provides.¹⁰

The statewide cap under HB 1217 is therefore both the floor and the ceiling for rent regulation in Snohomish County. A local city council cannot adopt a stricter 5% cap, and the county cannot add limits beyond what the legislature enacted. The one exception in the preemption statute is for publicly owned or publicly assisted properties, where governments can negotiate rent restrictions as part of tax exemption or financing agreements.⁹

1
Washington State Department of Commerce. HB 1217 Landlord Resource Center
2
Washington State Legislature. RCW 59.18.140 – Reasonable Obligations or Restrictions
3
Washington State Legislature. HB 1217 – 2025-26 Bill Summary
4
Washington State. Landlord-Tenant
5
Washington State Legislature. RCW 59.18.240 – Reprisals or Retaliatory Actions by Landlord Prohibited
6
Washington State Legislature. RCW 59.18.250 – Reprisals or Retaliatory Actions by Landlord – Presumptions – Rebuttal – Costs
7
U.S. Department of Housing and Urban Development. Housing Discrimination Under the Fair Housing Act
8
Washington State Legislature. RCW 59.18.255 – Source of Income Discrimination
9
Washington State Legislature. RCW 35.21.830 – Controls on Rent
10
Washington State. Authority of Local Governments to Impose Rent Control