What Is Mello-Roos?

What Mello-Roos actually is

Mello-Roos is a special tax authorized under California's Mello-Roos Community Facilities Act of 1982 (California Government Code § 53311 et seq.). A local government forms a Community Facilities District (“CFD,” a term you will often see used interchangeably with Mello-Roos), issues bonds, and repays them with an annual special tax charged to every parcel inside the district. Forming a CFD requires approval by two-thirds of the district's voters, or of its landowners where fewer than 12 registered voters live in the proposed district, per the San Diego County Assessor's Mello-Roos overview.

The charge shows up as its own line item, separate from the regular property tax, which runs at roughly 1.1% of assessed value once the Proposition 13 (Prop 13) base rate and local voter-approved levies are included. Treat 1.1% as a countywide blended estimate, noting that local lender guides put most effective rates between about 1.04% and 1.22%, and look up any parcel's exact rate through the county's Tax Rate Area search.

The money funds infrastructure that a newly developed area needs but that the existing tax base can't yet support. The Act and the county's summary of it list schools, roads, sewer and water lines, parks, libraries, and police and fire facilities among the eligible uses. Buyers in communities built in the last few decades will find a real chance Mello-Roos applies, as a lot of San Diego's inland and North County growth falls into this bucket. The county's FY 2025-26 active district list runs to hundreds of CFDs across cities, school districts, fire districts, and water districts.

Why it exists: the Prop 13 backstory

To understand Mello-Roos, it helps to understand Proposition 13. Passed in June 1978, Prop 13 capped the general property tax at 1% of assessed value, limited assessment growth to 2% per year, and reset assessments to the purchase price only when a property sells, as the State Board of Equalization explains. A significant win for existing owners, Prop 13 also stripped cities, counties, and school districts of much of the financing capacity they'd relied on to build infrastructure for growing areas. A newly built subdivision needs roads and schools on day one, not decades from now when its tax base catches up.

The legislature's answer, four years later, was the Mello-Roos Act. It was named for its two authors, state Senator Henry Mello and Assemblyman Mike Roos, and enacted specifically in response to Proposition 13, per the Orange County Treasurer-Tax Collector. It let local agencies form a CFD, get landowner or voter approval, issue bonds against a dedicated special tax, and build the infrastructure up front. Because it's a special tax tied to a specific district and purpose (not the general ad-valorem property tax), it sits outside Prop 13's 1% cap. The same Prop 13 mechanism is also what causes the supplemental tax bill surprise many buyers hit a few months after closing, a related but separate cost.

Typical costs by San Diego community

Mello-Roos amounts vary enormously by district, bond series, and even the specific phase of a development, so there's no single countywide number. The charge isn't based on a home's value. Each district sets a formula (its Rate and Method of Apportionment) keyed to property characteristics like square footage and lot size, with a defined maximum tax and annual increase. The ranges below are illustrative, drawn from community-level patterns rather than a specific parcel, and are meant to give a sense of scale, not a quote. Always confirm the exact figure for a specific address before relying on it.

• Eastlake (Chula Vista): roughly $1,500–$4,000 per year, varying by neighborhood and bond series. The county's active CFD list shows separate Eastlake districts (CFD 06-I, 07M, and others) alongside Chula Vista Elementary and Sweetwater Union High School District CFDs.
• Otay Ranch (Chula Vista): one of the larger master-planned CFD areas in the county, often $4,000–$8,000 or more per year depending on the village and phase. A single parcel here can sit inside several districts at once (city, elementary, and high school district CFDs each billing their own line item), and local guides group Otay Ranch among the county's highest Mello-Roos areas at $3,000–$10,000+ per year.
• Black Mountain Ranch (San Diego): the City of San Diego's CFD No. 4 (Black Mountain Ranch Villages) bonds mature September 1, 2037, with the final levy anticipated in 2036–37 , after which that portion of the charge goes away entirely. Note the same area also carries a Poway Unified School District CFD (CFD No. 12), which runs on its own schedule.
• Pacific Highlands Ranch and Carmel Valley (San Diego): both carry active school-district CFDs. The county's FY 2025-26 list shows San Dieguito Union High School District, Del Mar Union, Solana Beach, and North City West (Carmel Valley's original planning-area name) districts levying here. Amounts vary by specific tract.

The only reliable way to get a real number is to check the parcel itself, either through the county's public Special Assessments portal, or through a tool like sounding that queries it for you.

How long it lasts

Bond-backed Mello-Roos isn't permanent. It's tied to bonds with a fixed term, and the special tax ends once those bonds are paid off, though some districts continue a smaller levy afterward to maintain the improvements or fund ongoing services, so buyers should check which kind applies. The City of San Diego's CFD FAQ caps its district bonds at 30 years from initial issuance, with authorized levy windows generally spanning 25 to 50 fiscal years; its districts' bonds mature between 2020 and 2037 depending on the district. Black Mountain Ranch's 2036–37 retirement window (noted above) is a real example of a bond maturity within many current buyers' likely ownership horizon. When evaluating a home with Mello-Roos, ask how many years remain on the underlying bonds. A district a few years from payoff represents a very different long-term cost than one that issued new bonds recently.

Is it tax-deductible?

Generally, no (at least not the way the base property tax is). Internal Revenue Service (IRS) Publication 530 allows a deduction for real estate taxes assessed uniformly against all property for general community purposes, and disallows assessments for local benefits that increase a property's value (streets, sidewalks, water and sewer systems), which is the category most Mello-Roos charges fall into. There is a narrow exception for the portion of an assessment covering maintenance, repair, or interest, if the bill breaks it out. California's Franchise Tax Board (FTB) has taken the same position for state returns, treating only ad-valorem taxes as deductible. This is a general rule with real nuance in how it applies to a specific bill. A tax professional can advise on a specific situation, and this isn't tax advice.

How to check your own address

There are a few ways to find out whether a specific property carries Mello-Roos:

• Look at the seller's current property tax bill. CFD/Mello-Roos charges are itemized as their own lines, separate from the base ad-valorem tax, with the levying district's name and phone number, per the City of San Diego's CFD FAQ.
• Check the county's Special Assessments portal directly for the parcel. The Assessor's step-by-step instructions walk through it.
• Ask your agent for the preliminary title report or natural hazard disclosure package. Forming a CFD requires recording a Notice of Special Tax Lien, so title searches flag it, and California Civil Code § 1102.6b requires sellers to make a good-faith effort to disclose the special tax.
• Or skip the manual digging: enter the address into sounding and it pulls the same county Special Assessments data straight into the monthly cost breakdown, right alongside the base tax, financing, and everything else.