Diamond Bar property tax: where it goes
A Diamond Bar house pays 1.174% of its taxable value in property tax, plus flat charges on the same bill. For a house at $620,444 of value before exemptions with the homeowners' exemption, that's about $7,454 a year.
Tax is levied on the full value of taxable property.
Who taxes this house
| Taxing agency | Rate | On $620,444 |
|---|---|---|
| 1% general levy (countywide) | 1% | $6,134 |
| Walnut Valley Unified bonds (schools) | 0.1056% | $648 |
| Mt. San Antonio College bonds (schools) | 0.0597% | $366 |
| Metropolitan Water District | 0.0085% | $52 |
| LA County Measure W Safe Clean Water tax (median single-family parcel) | flat | $109 |
| LA County Fire Measure E special tax (estimate, median-size home) | flat | $125 |
| San Gabriel Valley Mosquito and Vector Control assessment | flat | $20 |
| Total | 1.174% | $7,454 |
2026-27 tax year, Los Angeles County. Exemptions applied: Homeowners' exemption ($7,000).
Ways to pay less
- Low-income seniors over 62: Safe, Clean Water parcel tax exemption. Owners over 62 who live in the home and head a low-income household can apply for an exemption from the Safe, Clean Water Program special parcel tax; the FY 2027-28 limit is $106,600 for a 2-person household. How: Submit the claim form to the Safe, Clean Water Program by May 1 each year; call 833-275-7297.
Dates
| When | What |
|---|---|
| Nov 30, 2026 (in 38 days) | Last day to file a 2026 regular assessment appeal in LA County (filing runs July 2 to November 30). |
| Dec 10 (in 48 days) | First property tax installment (due Nov 1) is late after Dec 10: 10% penalty. |
| Feb 15 | Last day for a first-time homeowners' exemption claim to get the full exemption for the year. |
| Apr 10 | Second property tax installment (due Feb 1) is late after Apr 10: 10% penalty plus $10. |
Pay or manage it
Sources
- LA County FY 2026-27 tax rate resolution
- Metropolitan Water District FY 2026/27 tax rate resolution
- California BOE: homeowners' exemption
- Safe, Clean Water Program: tax appeal procedures and guidelines
- LA County Public Works Safe Clean Water tax layer description
- Safe, Clean Water Program: FY 2027-28 low-income senior exemption form
- LA County Treasurer and Tax Collector: secured property tax FAQ
- LA County Assessment Appeals Board
Checked October 22, 2026. Every number here comes from the public sources listed, matched by our checker.
Rates change every year; this page shows when it was last checked. Nothing here is legal, tax or insurance advice.