What is a CPI-linked rent increase in Washington?

A CPI-linked rent increase ties the annual rent adjustment to the federal Consumer Price Index. Washington statewide rent caps that include a CPI factor (such as California's AB 1482, which uses 5 percent plus regional CPI capped at 10 percent total) measure CPI for the relevant region in the 12 months preceding the increase. A landlord using CPI-linked rent in a non-rent-cap Washington jurisdiction can use any CPI measure (national, regional, or "all urban consumers" CPI-U), but the lease must specify which one and the calculation method. Tenants should verify the math: published CPI numbers are public on the Bureau of Labor Statistics website, and a 1 percent error in CPI calculation on a 1-year tenancy at $1,500 rent is $180 over-paid. Washington HB 1217 (2024) requires 90 days advance notice for any rent increase, prohibits any increase during the first 12 months, and caps annual increases at the lower of CPI + 7% or 10% flat. Buildings under 12 years old are exempt. The rent cap framework sunsets July 1, 2040.

Source: RCW 59.18.140 (90-day advance notice for any rent increase, HB 1217)