LA County Caps Rent on Older Altadena Apartments at 1.919% Through June 2027

The short answer

Altadena isn't part of any city, so LA County writes its rent rules. The county law is the RSTPO, the Rent Stabilization and Tenant Protections Ordinance. It has two rules:

• The rent cap limits how much you can raise the rent each year. Right now it's 1.919% for most covered units.
• The eviction rule means you need a reason the law allows to end a tenancy.

Most Altadena rentals fall under the eviction rule. The rent cap reaches fewer homes, mainly older buildings with two or more units.

Find your rental in the table. Each row has its own section below.

"Built" here means the date on the certificate of occupancy. That's the government's sign-off that a building can be lived in.

Some rentals are exempt from both rules. To check your address, enter it in the county's Rent Registry under "FIND." Or ask DCBA, the county's Department of Consumer and Business Affairs, listed below.

A house or condo

A house or condo is exempt from the county rent cap. The eviction rule still applies, and the county calls these units "partially covered."

The state's rent cap, AB-1482, may still apply. A house or condo skips the state rules only if it passes three tests. One test is that it can be sold by itself. A house with an ADU on the lot fails that test. An ADU is a backyard or accessory unit. The AB-1482 recap explains all three.

If you have an ADU on the lot, ask DCBA how the county treats your property.

If you rent a house or condo: your rent isn't capped by the county. The owner still needs an allowed reason to end your tenancy.

Older buildings with two or more units

An older building with two or more units falls under the rent cap. Its certificate must be dated on or before February 1, 1995. It also falls under the eviction rule.

You can raise rent once every 12 months, with 30 days' written notice. First, the county requires you to register each covered unit and pay the yearly fee.

If you rent in an older building: if you think an increase broke the rules, you can ask DCBA to review it.

Newer buildings

A building with a certificate dated after February 1, 1995 is exempt from the county rent cap. The eviction rule still applies, unless an exemption fits.

The state cap also skips buildings whose certificate is less than 15 years old. See the AB-1482 recap.

Buildings rebuilt after the Eaton Fire

A rebuilt building gets a new certificate, so it's exempt from the county rent cap. The eviction rule still applies.

After the fire, the county's price-gouging protections also limited rent increases. That limit ended on May 28, 2026, according to a report from the LA City Attorney. Ask DCBA whether any other limit applies to your unit.

If you hope to return to a rebuilt unit: the rent may be higher than before. The eviction rule still applies to the unit.

When the eviction rule starts

Under state law, the eviction rule starts after 12 months. The county's published pages don't say whether its rule starts on day one or after a wait. If timing matters for your tenancy, ask DCBA.

How the rent cap is set

The county cap is 60% of the yearly rise in the Consumer Price Index (CPI). The CPI is a government measure of inflation, here over the 12 months ending in September.

The cap has three tiers, each with a hard ceiling:

On a $2,400 monthly rent, the general cap allows about $46 a month.

Check DCBA's current bulletin before you rely on these rates.

What the RSTPO is

The RSTPO is LA County Code Chapter 8.52. Its permanent version took effect April 1, 2020.

The county changed the formula to the current one on January 1, 2025.

It covers all unincorporated areas of LA County, including these SGV-area places:

• Altadena
• East Pasadena
• Hacienda Heights
• Rowland Heights

It sits on top of state law. The single-family guide shows how the state, county, and city layers stack.

It doesn't apply inside any city. Pasadena, next door, runs its own rule, Measure H. If your property is inside a city, check with that city.

Who to contact

• Landlords and renters can get answers from these offices for free.
• LA County Department of Consumer and Business Affairs (DCBA), Rent Stabilization Program (both). Runs the RSTPO, answers coverage and rent increase questions, and offers mediation. Phone: (800) 593-8222. Email: rent@dcba.lacounty.gov. Website: dcba.lacounty.gov/rentstabilizationprogram. Walk-in: 320 W. Temple St., Room G-10, Los Angeles, CA 90012.
• DCBA office in Altadena (both). Altadena Community Center, 730 E. Altadena Dr., Altadena, CA 91001. Fridays only, 9 a.m. to 5 p.m. Phone: (626) 398-6174.
• Rent Registry (both). Landlords register covered units and pay the yearly fee here. Anyone can look up an address to check coverage. Tenants can create an account to ask for a rent adjustment. Website: rentregistry.dcba.lacounty.gov.
• Stay Housed L.A. (renters). Free legal help and eviction defense for LA County renters who qualify. Phone: (888) 694-0040. Website: stayhousedla.org.
• Housing Rights Center (both). Free housing counseling and fair housing help, including in unincorporated LA County. Phone: (800) 477-5977. Website: housingrightscenter.org.

Before you act

This article is general information, not legal advice. Laws change, and every property is different. Before you act, talk to a licensed California real estate attorney. For tax questions, also talk to a CPA.