A property tax lien is a lien or claim for money due to a federal, state, or local government for unpaid and delinquent taxes. For example, the federal government may place a lien on a homeowner’s home or other real property for unpaid federal income taxes, and state and local governments (often counties) may place a lien on real property for unpaid income or property taxes.

The federal, state, or local government entity—also known as a taxing authority—may seek to recover payment for unpaid taxes by forcing the sale of the property on which the lien is placed in the foreclosure process—a process in which the validity of the lien and satisfaction (payment) for the lien is litigated or determined in court.

In New Mexico (NM), a property tax lien represents a legal claim against a property by a governmental entity due to unpaid property taxes. When property taxes are delinquent, the county in which the property is located may place a lien on the property. This lien ensures that the tax authority has a legal claim to the property's value up to the amount of the unpaid taxes, plus any interest and penalties. If the taxes remain unpaid, the county can initiate a foreclosure process to enforce the lien, which may result in the sale of the property at a public auction. The process is governed by state statutes, specifically under the New Mexico Property Tax Code. The foreclosure process involves court proceedings to confirm the validity of the lien and to determine the final satisfaction of the debt through the sale of the property. Federal tax liens for unpaid income taxes can also be placed on real property, and these liens take priority over most other liens, including those by local governments.