CPI rent increases: how inflation sets the limit
Most rent caps in the U.S. are tied to the Consumer Price Index (CPI): the allowed increase is a fixed percentage plus inflation, with a ceiling. Here is which index each law uses and what it allows right now.
Inflation data: BLS, latest month September 2026; figures cross-checked against the official publications. Last site change: November 8, 2026 (changelog).
What is the CPI?
The Consumer Price Index for All Urban Consumers (CPI-U), published monthly by the Bureau of Labor Statistics, measures how prices of a basket of goods and services change. Rent laws use a 12-month change: for example April to April for a metro area. A CPI of +3.7% plus California's 5% gives a cap of 8.7%.
Statewide caps tied to the CPI
| Where | Increases taking effect | Cap | How it is calculated |
|---|---|---|---|
| California: Los Angeles or Orange County | August 1, 2026 – July 31, 2027 | 8.7% | Los Angeles-Long Beach-Anaheim, CA CPI-U: April 2025 342.565 → April 2026 355.166 = +3.7%. 5% + CPI, max 10%; matches the figure published by the California Attorney General (8.7%). |
| California: Alameda, Contra Costa, Marin, San Francisco or San Mateo County | August 1, 2026 – July 31, 2027 | 8.8% | San Francisco-Oakland-Hayward, CA CPI-U: April 2025 355.707 → April 2026 369.215 = +3.8%. 5% + CPI, max 10%; matches the figure published by the California Attorney General (8.8%). |
| California: Riverside or San Bernardino County | August 1, 2026 – July 31, 2027 | 8.1% | Riverside-San Bernardino-Ontario, CA CPI-U: March 2025 136.511 → March 2026 140.728 = +3.1%. 5% + CPI, max 10%; matches the figure published by the California Attorney General (8.1%). |
| California: San Diego County | August 1, 2026 – July 31, 2027 | 8.2% | San Diego-Carlsbad, CA CPI-U: March 2025 384.88 → March 2026 397.284 = +3.2%. 5% + CPI, max 10%; matches the figure published by the California Attorney General (8.2%). |
| California: Any other California county | August 1, 2026 – July 31, 2027 | 8.6% | Cost-of-living figure from the California CPI-U (Dept. of Industrial Relations). 5% + CPI, max 10%; matches the figure published by the California Attorney General (8.6%). |
| Oregon | January 1, 2026 – December 31, 2026 | 9.5% | CPI-U West Region, 12-month average to September 2025: +2.6%. 7% + CPI, max 10%. Official figure for 2026 published by Oregon's Office of Economic Analysis: 9.5%. |
| Oregon | January 1, 2027 – December 31, 2027 | 10% | 7% + CPI, max 10%. Official figure for 2027 published by Oregon's Office of Economic Analysis: 10%. |
| Washington | January 1, 2026 – December 31, 2026 | 9.683% | Seattle-Tacoma-Bellevue CPI-U: June 2024 354.824 → June 2025 364.344 = +2.683%. 7% + CPI, max 10%. Official figure published by the Washington Department of Commerce: 9.683%. |
| Washington | January 1, 2027 – December 31, 2027 | 10% | Seattle-Tacoma-Bellevue CPI-U: June 2025 364.344 → June 2026 380.849 = +4.530%. 7% + CPI, max 10%. Official figure published by the Washington Department of Commerce: 10%. |
Local rent control tied to the CPI
| Program | Current allowed increase | Rule |
|---|---|---|
| Los Angeles Rent Stabilization Ordinance (RSO) | 3% (July 1, 2026 – June 30, 2027) | 90% of the change in the Los Angeles-area CPI (12 months ending September 30), at least 1% and at most 4%. In force since February 2, 2026 (Council File 23-1134). |
| Los Angeles County Rent Stabilization and Tenant Protections Ordinance (RSTPO) | 1.919% (July 1, 2026 – June 30, 2027) | 60% of the change in the average CPI over the 12 months ending in September, at most 3%. Qualifying small property landlords may add 1% (max 4%), luxury units 2% (max 5%). |
| San Francisco Rent Ordinance | 1.6% (March 1, 2026 – February 28, 2027) | 60% of the increase in the Bay Area CPI-U, at most 7%. Announced each year, effective March 1 to the end of February. |
| Berkeley Rent Stabilization Ordinance | 1.0% (January 1, 2026 – December 31, 2026) | 65% of the Bay Area CPI-U change (July to June of the prior year), at most 5%. Adopted by the Rent Board each October, effective January 1. Unused adjustments may be banked. |
| Santa Monica Rent Control Law | 2.6% (max $70) (September 1, 2026 – August 31, 2027) | 75% of the change in the Los Angeles-area CPI for the 12 months ending in March, with a dollar ceiling set by the Rent Control Board. Effective September 1 each year. |
| Oakland Rent Adjustment Program | 2.3% (August 1, 2026 – July 31, 2027) | 60% of the change in the Bay Area CPI-U, at most 3%. Effective each August 1. |
| D.C. Rent Stabilization Program | 4.1% (2.1% elderly or disabled) (May 1, 2026 – April 30, 2027) | General: Washington-area CPI-W plus 2% (2026: 2.1% + 2%). Registered elderly (62+) or disabled tenants: the lowest of the Social Security cost-of-living adjustment, the CPI-W or 5% (2026: 2.1%). |
| Montgomery County Rent Stabilization (County Code Chapter 29) | 5.2% (July 1, 2026 – June 30, 2027) | Washington-area CPI-U plus 3%, capped at 6% (2026: 2.2% + 3% = 5.2%; 2025: 2.7% + 3% = 5.7%; 2024: capped at 6%). Set by DHCA each year for July 1 through June 30. |
CPI clauses in leases
Outside capped areas, a lease may tie future increases to the CPI (an escalation clause), for example “rent rises each year by the change in the CPI-U for the metro area, at least 2%, at most 5%”. Such a clause only works if the lease names the index, the months compared and the date the change applies. It does not override a statewide or local cap, which still limits the result.
Work it out
New rent = current rent × (1 + cap ÷ 100). With a $2,000 rent and a cap of 8.7%: $2,000 × 1.087 = $2,174. The rent increase calculator picks the right period and region automatically.
Sources: BLS CPI-U series; statutes linked on each calculator page. Not legal advice.