An IRS tax lien may occur when there is a large sum of money owed to the IRS. The IRS can then put a “lien” on your property. This means that the owner is not able to sell or refinance the property until they have satisfied the IRS.
A tax lien will also make it difficult to simply give the property away. More or less, despite technically being the owner, when IRS tax liens are imposed, those who owe money have limited rights to their property.