The headline number: 1.0–1.25%
California's Proposition 13 caps the base property tax rate at 1% of assessed value. But voter-approved bonds, parcel taxes, and Mello-Roos special assessments push the effective rate to ~1.05–1.25% in most San Diego neighborhoods — and well above that in some newer master-planned communities.
How Prop 13 works
- When you buy, your assessed value resets to your purchase price.
- Each year after, the assessed value can increase by at most 2%.
- So if you bought a $1M home in 2026, your max assessment in 2027 is $1.02M, in 2028 is $1.0404M, etc. — even if the home now appraises at $1.5M.
This is why long-time owners often pay much less than newer neighbors with identical homes. A house bought in 1995 for $250K and appraised today at $1.4M is still taxed on ~$420K of assessed value.
Components of your tax bill
| Line | What it is | Typical amount |
|---|---|---|
| 1% base rate | Prop 13 cap | 1.000% |
| Voter-approved bonds | School, water, infrastructure | 0.05–0.20% |
| Parcel taxes | Flat fees, e.g. $96/yr lighting | $50–$400/yr |
| Mello-Roos (CFD) | Newer-community infrastructure bonds | $1,500–$5,000/yr |
Mello-Roos by neighborhood
Mello-Roos applies to communities developed under California's Community Facilities Districts Act (1982+). It funds new schools, roads, parks. Typical San Diego incidence:
| Area | Typical Mello-Roos |
|---|---|
| Carmel Valley (newer) | $2,000–$3,500/yr |
| 4S Ranch / Del Sur | $3,000–$5,000/yr |
| Otay Ranch / Eastlake | $2,000–$4,500/yr |
| Santaluz / Pacific Highlands | $3,500–$6,000/yr |
| Coronado, La Jolla, North Park | None (older) |
| Mission Hills, South Park, Encinitas (older) | None to minimal |
Mello-Roos has a defined sunset — typically 20–40 years from when the bonds were issued. Always ask the seller (or your title officer) when the CFD obligation ends.
The supplemental tax bill (the surprise)
When you buy, the county reassesses to your purchase price. They then send you a supplemental tax bill covering the gap between the previous owner's assessed value and yours, prorated from your closing date through the end of the fiscal year (June 30).
This bill arrives 3–9 months after closing and is NOT paid through your escrow account. Plenty of San Diego buyers miss this and get hit with an unexpected $4,000–$15,000 bill. Set aside cash for it.
On a $1M purchase from someone whose assessed value was $400K, the supplemental bill is roughly: ($600K × 1.05%) × (months remaining in fiscal year / 12). If you close in November with 8 months left, that's ~$4,200.
Realistic monthly tax in your payment
Lenders escrow 1/12 of your annual tax. For budgeting purposes, use:
- Older neighborhoods (no Mello-Roos): 1.05–1.10% × purchase price ÷ 12
- Newer master-planned (with Mello-Roos): 1.20–1.45% × purchase price ÷ 12
On a $1M home: $875–$917/mo (older), $1,000–$1,208/mo (newer). The difference is real money over 30 years.
Tax savings: the homeowner exemption
Sign the Homeowner's Exemption (BOE-266) after closing. Saves about $70/year. Tiny, but free money.
How to challenge your assessment
If you believe your assessed value exceeds market value (rare in a rising market, common in a falling one), file a Decline-in-Value Application (Prop 8) with the County Assessor between July 2 and November 30. They reassess and adjust if warranted.