Basis - Property Received as a Gift

Per IRS Publication 551 Basis of Assets, on page 9:

Property Received as a Gift

To figure the basis of property you receive as a gift, you must know its adjusted basis (defined earlier) to the donor just before it was given to you, its FMV at the time it was given to you, and any gift tax paid on it.

The cost basis would depend on whether or not the fair market value of the property is less than, equal to, or more than the donor's adjusted basis. Please see the publication for details.

Note that any link in the information above is updated each year automatically and will take you to the most recent version of the document at the time it is accessed.