Adverse possession—sometimes called squatter's rights—occurs when a person or entity who does not own a certain piece of real property occupies or uses it in a way that is adverse to the owner of the property—meaning the use is in conflict or at odds with the property owner’s interests.

If this adverse possession or use of the property meets the legal standard for adverse possession—often described as use that is continuous, exclusive, hostile, open, and notorious—and continues for the prescribed period of time (usually specified in the state statute)—the person or entity adversely possessing or using the property will acquire ownership of the property (title). This ownership will result in the changing of boundary lines.

Because the required adverse possession must be open, obvious, and adverse to the owner’s interests, title may only be acquired by adverse possession to the portion of property that is used in that way.

Adverse possession laws vary from state to state and may be located in a state’s court opinions (also known as common law or case law) or, more often, in its statutes.

In Tennessee, adverse possession laws allow a person to claim ownership of a property if they have occupied it in a manner that is hostile, actual, open, exclusive, and continuous for a statutory period. The statutory period required for adverse possession in Tennessee is generally 7 years if the possessor has a color of title (a claim to title that appears valid but may be legally defective) and has paid the property taxes during that time. If there is no color of title, the period extends to 20 years. Tennessee law also requires that the use of the property be notorious, meaning it is known by others and not done in secret. The claimant must not have the owner's permission to use the property, as that would negate the 'hostile' requirement. If all conditions are met, the adverse possessor may be able to acquire legal title to the property. However, adverse possession claims can be complex, and it is often advisable to consult with an attorney to navigate the legal intricacies involved.