Property tax in Union County, New Mexico
The median property tax bill in Union County, New Mexico is $859 a year, which is about 0.7% of the county's median home value of $122,700. That effective rate is higher than the typical New Mexico county (0.55%) and lower than the national median (0.81%). These are American Community Survey 5-year estimates (2024); your own bill depends on your home's assessed value and any exemptions.
Estimate the property tax on a home in Union County
Enter a home's market value for a ballpark at Union County's average effective rate of 0.7% (Census). The real bill depends on the home's assessed value, the millage where it sits and any exemptions.
Estimated property tax: $859 / year
Property tax in Union County at a glance
| Measure | Value |
|---|---|
| Median annual property tax | $859 |
| Median home value | $122,700 |
| Effective tax rate | 0.7% |
| Typical New Mexico county rate | 0.55% |
| National median county rate | 0.81% |
Effective rate = median real estate taxes paid divided by median home value. Source: U.S. Census Bureau, American Community Survey 5-year estimates.
How does Union County compare in New Mexico?
Among New Mexico's 33 counties, Union County has the 6th highest effective property-tax rate: 5 rank higher and 27 rank lower. That is on the higher side for New Mexico. Nationally, it ranks 1900th of 3135 US counties by effective rate. See every New Mexico county ranked.
How much do homeowners in Union County actually pay?
The median is only the middle bill. Across Union County's 1,041 owner-occupied homes, 3.1% pay $3,000 or more a year in property tax, 6.5% pay at least $2,000, and 41.2% pay under $800. Another 6.7% report paying no property tax at all, which usually means an exemption covers the whole bill.
| Annual bill | Homes | Share |
|---|---|---|
| Under $800 | 429 | 41.2% |
| $800 to $1,499 | 391 | 37.6% |
| $1,500 to $1,999 | 84 | 8.1% |
| $2,000 to $2,999 | 35 | 3.4% |
| $3,000 or more | 32 | 3.1% |
| No property tax paid | 70 | 6.7% |
Owners with a mortgage pay a median of $933 and owners without one pay $626. Owners who have paid off a home have usually held it longer, and in states that cap how fast an existing owner's assessment can rise, long-held homes carry lower assessed values. Census table B25103.
How does the Union County property tax bill compare with local incomes?
The median property tax bill of $859 is about 1.4% of the median income of Union County homeowner households, $60,865 a year. That compares two middles, so a retiree in a long-held home can pay a far larger share. 72.4% of Union County's occupied homes are lived in by their owners; renters pay property tax too, just folded into rent.
Have property taxes gone up in Union County?
Yes. The median bill went from $457 in 2015-2019 to $859 in 2020-2024, a 88% rise. Over the same span the median home value moved 39.4%, from $88,000 to $122,700. Bills rose faster than values, which usually means local rates went up or an exemption shrank.
Two Census ACS 5-year periods with no survey years in common, in each period's own dollars. A change counts only if it exceeds the combined 90% margin of error.
Property tax in counties next to Union County
Union County borders 8 counties, 5 of them across the state line.
| County | Effective rate | Median bill | Median home value |
|---|---|---|---|
| Dallam County, TX | 1.15% | $1,736 | $151,400 |
| Hartley County, TX | 1.01% | $2,645 | $262,500 |
| Union County, NM (this county) | 0.7% | $859 | $122,700 |
| Quay County, NM | 0.61% | $532 | $87,200 |
| Colfax County, NM | 0.52% | $867 | $167,200 |
| Baca County, CO | 0.44% | $545 | $122,900 |
| Harding County, NM | 0.44% | $305 | $70,000 |
| Cimarron County, OK | 0.4% | $395 | $98,600 |
| Las Animas County, CO | 0.23% | $535 | $237,600 |
How is a home assessed in Union County?
New Mexico assesses homes at 33.33% of market value in every county, Union County included. How New Mexico assesses and reappraises homes.
Is there a homestead exemption in Union County?
Yes, for a head of family. New Mexico's exemption takes $2,000 off taxable value, often saving $50 to $90 a year. That is the New Mexico rule, and it applies in Union County. New Mexico's exemptions and relief programs in full.
When are property taxes due in Union County?
County treasurers mail bills around November 1. Tax is payable in two equal installments, the first due November 10 and the second due April 10 of the following year. You get a one month grace period on each: interest starts if the first half is not paid by December 10 or the second half by May 10.
New Mexico splits the bill into 2 installments. That is the New Mexico rule. Union County issues and collects the bill, so the dates printed on your statement are the ones that bind you.
How to appeal your Union County property assessment
You contest the assessed value with the the county valuation protests board, reached by petitioning the county assessor. The filing deadline is typically 30 days after the assessor mails your notice of valuation. That is the New Mexico rule; Union County sets the exact dates and forms. The New Mexico appeal process step by step.
New Mexico rules from primary state sources, reviewed September 7, 2026; sources on the New Mexico page.
Work out your own numbers
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How much house can I afford?
Your income, debts and down payment against the 28/36 rule lenders actually use, with Union County's tax rate to hand.
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Mortgage calculator
Monthly payment with principal, interest, tax and insurance, plus what an extra payment saves you.
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New Mexico income tax
Brackets, standard deduction and what New Mexico actually taxes.
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Sales tax in Union County
The other local tax: combined state and local rate for this county.
Sources
- Median real estate taxes paid and median home value for Union County, New Mexico: U.S. Census Bureau, American Community Survey 5-year estimates (2020-2024), tables B25103, B25077, B25102, B25119 and B25003; the five-year comparison uses the 2015-2019 estimates. Neighboring counties: Census county adjacency file.