Updated July 24, 2026
The LA City Rent Stabilization Ordinance covers buildings within Los Angeles with a certificate of occupancy before October 1, 1978 and two or more units. New formula effective July 2026: 90% CPI with 4% ceiling.
One clarification worth making up front: RSO is a City of Los Angeles ordinance, not a statewide California law — there is no single "California RSO." Search interest for "California RSO" almost always means one of two things: this LA City ordinance specifically, or the statewide floor that applies everywhere RSO doesn't — AB 1482, the California Tenant Protection Act. If your building is outside LA City limits, AB 1482 is the relevant state law, not RSO, though a separate county-level ordinance (RSTPO) may also apply in unincorporated LA County.
RSO caps annual rent increases on covered buildings, requires just cause for evictions, and mandates annual LAHD registration. The current allowable increase (July 2025–June 2026) is 3%. The new formula (effective July 1, 2026) is 90% of CPI, floor 1%, ceiling 4%. The December 2025 RSO rewrite is the largest change to LA rent control in a decade and actively reprices pre-1978 LA City multifamily through 2026 — full detail in what the 2026 RSO rewrite means for your building and the LA RSO rent cap explainer.
Roughly 70% of LA City multifamily is RSO-covered. Pre-1978 buildings in Koreatown, Hollywood, Palms, Mid-City, Mar Vista, and most of the LA City Valley fall under RSO. The July 2026 formula change has already expanded cap rates 20-40 basis points on this inventory.
If you're selling an RSO building, buyers underwrite the capped rent trajectory, not the market rents you might wish you could charge — the same dynamic that separates RSO-covered buildings from Costa-Hawkins-exempt ones. Documenting current RSO registration status and rent history accurately is part of presenting a building buyers can underwrite without discounting for uncertainty. See how rent control affects your sale price.
If you're buying, confirm RSO status from the certificate-of-occupancy date directly — don't assume from the building's apparent age. A building that looks 1970s but was substantially rebuilt after October 1, 1978 may not be covered, and the reverse mistake is just as costly.
Is RSO the same thing as California rent control?
No. RSO is a City of Los Angeles ordinance. California's statewide rent-control floor is AB 1482, which applies more broadly (including buildings RSO doesn't reach) but caps increases less aggressively than RSO does. A building can be subject to AB 1482, RSO, both, or neither, depending on jurisdiction and construction date.
Which buildings does RSO cover?
Multifamily buildings within the City of Los Angeles with a certificate of occupancy before October 1, 1978, and two or more units. Single-family homes and condos are generally exempt, along with post-1978 construction — see Costa-Hawkins for how that exemption works.
How much can I raise rent on an RSO unit?
3% for the current cycle (July 2025–June 2026). Starting July 1, 2026, the formula changes to 90% of CPI, with a 1% floor and 4% ceiling — replacing the prior formula, which had no floor and a higher ceiling.
Does RSO apply outside the City of Los Angeles?
No — RSO is specifically a City of LA ordinance. Unincorporated LA County has its own, separate ordinance (RSTPO). Other California cities have their own local rent-control ordinances, distinct from LA's RSO, subject to the same Costa-Hawkins limits.
Thinking about selling? Get a no-obligation evaluation on your building.
Request Free Evaluation →