Census tract codes for a specific address can be found using the Census Geocoder tool at the website of the United States Census Bureau. Users of this tool can input a street address in order to find out which census tract it is situated in.
Alternatively, there is a tool at the website of the Federal Financial Institutions Examination Council that allows users to check their address for its associated tract geocode. This tool is intended for financial institutions and is based on commercial data for recent activity years.
Other ways to identify census tracts for an address include the U.S. Census Bureau's TIGERweb mapping application or their PDF tract reference maps.