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San Mateo has never adopted its own local rent control ordinance, which sets it apart from several neighboring Bay Area cities that have. That doesn't mean rent increases here are unregulated. California's statewide Tenant Protection Act, AB 1482, still caps how much most San Mateo landlords can raise rent each year, and the actual allowed percentage changes annually based on regional inflation data. Getting this number wrong, in either direction, is one of the more common mistakes we see from San Mateo owners.
Key Takeaways
San Mateo has no local rent control ordinance, so AB 1482's statewide cap is the only rent increase limit applying to covered properties.
Through July 31, 2026, the cap for San Mateo is 6.3 percent (5 percent plus the regional cost-of-living change for the San Francisco-Oakland-Hayward CPI region).
Single-family homes and condos are generally exempt under the Costa-Hawkins Rental Housing Act, provided specific notice language is included in the lease.
Properties built within the last 15 years on a rolling basis are exempt, meaning exemption status changes over time as buildings age past that threshold.
AB 1482's just cause eviction protections require a valid legal reason to end a tenancy after 12 months of occupancy and cover a broader range of properties than the rent cap itself.
Why San Mateo's Situation Is Different From Its Neighbors
Several cities in San Mateo County and the broader Bay Area have adopted their own local rent stabilization ordinances that go further than state law, some dating back decades. San Mateo itself has not, despite periodic local advocacy pushing for exactly that. This means San Mateo landlords operate under a single regulatory layer, AB 1482, rather than navigating both a state cap and a separate local ordinance the way owners in some nearby jurisdictions have to.
That's a genuinely simpler compliance picture, but it also means the state cap is the only ceiling in place, and it's worth confirming current local advocacy efforts before assuming this arrangement is permanent, since city councils in the region have revisited this question more than once in recent years. Our property management team monitors these local policy discussions specifically so our owners aren't caught off guard if San Mateo's regulatory landscape ever shifts.
The Actual Percentage You're Working With Right Now
AB 1482 caps rent increases at 5 percent plus the percentage change in the regional cost of living, with a hard ceiling of 10 percent regardless of how high inflation runs. San Mateo falls within the San Francisco-Oakland-Hayward CPI region, which covers Alameda, Contra Costa, Marin, San Francisco, and San Mateo counties together. For the period from August 2025 through July 31, 2026, that works out to a maximum allowable increase of 6.3 percent.
This figure recalculates annually based on April cost-of-living data, so a cap that applied to an increase last year isn't necessarily the same figure that applies to an increase you're planning today. Confirming the current percentage before sending any rent increase notice is worth the extra step, since using last year's figure by mistake is an easy way to send a technically invalid notice that a tenant's attorney can challenge on procedural grounds alone.
Which Properties Are Actually Exempt
Not every San Mateo rental falls under AB 1482's rent cap. Single-family homes and condominiums are generally exempt under the Costa-Hawkins Rental Housing Act, but that exemption isn't automatic; it requires the lease to include specific statutory notice language informing the tenant that the property is exempt. A single-family rental without that language in the lease may not actually qualify for the exemption it would otherwise be entitled to.
Properties built within the last 15 years are also exempt, but this is a rolling exemption rather than a permanent one, meaning a building constructed in 2012 will eventually age past that threshold and become subject to the cap for the first time. Our accounting team tracks these exemption dates for every property we manage so a rent increase never gets sent based on outdated exemption status.
Just Cause Protections Reach Further Than the Rent Cap
It's worth separating AB 1482's two main protections, since they don't always apply to the exact same set of properties. The just cause eviction requirement, which mandates a valid legal reason to end a tenancy once a tenant has occupied a unit for 12 months, generally applies to a broader range of properties than the rent cap does. A single-family home exempt from the rent cap under Costa-Hawkins can still be fully subject to AB 1482's just cause requirements.
Confirming which specific protection applies to a given property, rather than assuming exemption from one means exemption from both, protects a landlord from ending a tenancy without the legally required justification, a mistake that can turn a routine non-renewal into a wrongful eviction claim. Our tenant screening process factors these distinctions in from the start of every tenancy we place.
FAQ
Does San Mateo have its own local rent control ordinance?
No. San Mateo has never adopted a local rent stabilization ordinance, so AB 1482's statewide cap is the only rent increase limit that applies here.
What is the current maximum rent increase allowed in San Mateo?
6.3 percent for increases taking effect through July 31, 2026, based on the San Francisco-Oakland-Hayward CPI region that includes San Mateo County.
Are single-family homes exempt from the rent cap?
Generally, yes, under the Costa-Hawkins Rental Housing Act, but only if the lease includes the specific statutory notice language required to claim that exemption.
If my property is exempt from the rent cap, is it also exempt from just cause eviction requirements?
Not necessarily. The rent cap and just cause protections have different coverage rules, and a property exempt from one may still be fully subject to the other.
Getting the Numbers Right Every Time
AB 1482's rent cap changes every year, and San Mateo's lack of a local ordinance means this single state calculation is the only ceiling landlords here need to track, but tracking it accurately still matters. Confirming the current percentage, your property's exemption status, and whether just cause protections apply separately from the rent cap protects you from a rent increase notice or lease termination that doesn't hold up.
If you'd like help reviewing your current rent increase practices for a San Mateo rental, reach out to our team today.
