Los Alamos County, New MexicoProperty records & tax offices
Links open the listed public-office or service-provider website in a new tab. This directory does not collect payments.
Find the right property record
Use the property portal for ownership and assessed value, the collector for a bill or balance, and the map for parcel location. Have the address, owner name, or parcel number ready.
Tax bills & filing dates
These are the dates and qualifications recorded in the directory. Confirm your tax year and current deadline with the official office and your property’s notice.
- Tax bill mailing
- November 1, 2026; Los Alamos County states tax bills are mailed November 1 each year.
- Payment deadline
- First half due November 10, 2026; delinquent after December 10, 2026. Second half due April 10, 2027; delinquent after May 10, 2027.
- Assessment appeal
- April 1-May 1, 2026; Los Alamos County published a 2026 NOV mail date of April 1 and requires protests within 30 days.
Exemptions & appeals
View exemption application (opens in a new tab)Exemption filing
Within 30 days of the April 1, 2026 Notice of Value; Los Alamos County says current-year exemption applications must be filed within that period.
Senior relief
Los Alamos County's 2026 form: owner age 65+ or 100% disabled with 2025 modified gross income of $44,200 or less may qualify for the valuation freeze under NMSA 7-36-21.3.
Valuation limits
New Mexico NMSA 7-36-21.2 and 7-36-21.3 generally limit annual assessed-value growth for eligible residential property to 3%; statutory exceptions apply, and qualifying low-income owners age 65 or older or disabled may receive a valuation freeze.
For a valuation appeal, use the appeal date in the tax and filing section above. Keep your notice, supporting evidence, and proof of submission.
More exemption & appeal guidance →