Custer County, MontanaProperty 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
- October 2026; Custer County states real-estate tax bills are mailed in October each year.
- Payment deadline
- For tax year 2026, Montana real-property taxes are due by 5:00 p.m. November 30, 2026 for the first payment and May 31, 2027 for the second payment; if a due date falls on a weekend or holiday, the next business day applies.
- Assessment appeal
- For the 2025–2026 valuation cycle, file Form AB-26 or appeal to the county Tax Appeal Board within 30 days of the Department of Revenue classification/appraisal notice; late informal review was available through June 1, 2026. A written protest must also be filed with the county treasurer and disputed taxes paid under protest by the tax due date.
Exemptions & appeals
View exemption application (opens in a new tab)Exemption filing
The 2026 homestead/long-term-rental reduced-rate enrollment deadline was March 20, 2026. The 2027 enrollment window is May 4, 2026–March 1, 2027.
Senior relief
Montana Elderly Homeowner/Renter Credit: eligible Montana residents age 62+ with at least nine months of Montana residency, six months owning/renting a home, and total household income under $45,000 may claim a refundable credit up to $1,150. Montana also lists income-based Property Tax Assistance and Disabled Veteran Assistance programs. See https://revenue.mt.gov/property/property-tax-help/montana-elderly-homeowner-renter-credit.
Valuation limits
No county-specific annual valuation cap was verified. Montana residential property is valued every two years at 100% of market value; 2026 state classification/rate rules apply, including the reduced homestead tiered rates, while local treasurers apply locally set mill levies and special assessments.
For a valuation appeal, use the appeal date in the tax and filing section above. Keep your notice, supporting evidence, and proof of submission.