During the 2010 Type of Enumeration Area (TEA) Delineation, a TEA value was assigned to each 2010 Census collection block. The TEA value represents the type of enumeration and the geography where the Census Bureau conducts various field operations.

The 2010 TEA values are:

• TEA 1 = Mailout/Mailback
• TEA 2 = Update/Leave
• TEA 3 = Remote Update Enumerate
• TEA 4 = Remote Alaska
• TEA 5 = Update Enumerate
• TEA 6 = Military
• TEA 7 = Urban Update/Leave
• TEA 9 = Island Area List Enumerate

There were two phases to the 2010 TEA Delineation: Remote Area TEA Delineation and the Main TEA Delineation. The Remote Area TEA Delineation was conducted in Regional Offices starting September 5, 2006 and finishing September 28, 2006. TEA 3 and TEA 4 were the only TEAs delineated during this time.

The Main TEA Delineation was composed of a batch delineation, an interactive delineation, and a headquarters review of the 2010 TEAs. The other six TEAs were delineated during this time.

The batch portion of the Main TEA Delineation was performed by Geography Division on September 4, 2008. During this delineation, a TEA value was given to 2010 Census Bureau collection blocks based on pre-defined criteria. Many of the collection blocks were intentionally left blank, with a null TEA value.

The interactive portion of the Main TEA Delineation was performed in the Regional Census Centers starting September 16, 2008 and finishing December 31, 2008. The goal of the interactive delineation was to maximize Mailout/Mailback areas where practical, identify areas for TEA 5 and TEA 7, and smooth block TEA assignments into contiguous operational areas optimal for field operations.

A budget review was conducted on December 16, 2008. The Census Bureau determined that the proposed TEA areas fit within budget plans. The Field Division headquarters review of the TEA plans continued from January 2, 2009 through January 23, 2009. The Geography Division updated the Master Address File and Topologically Integrated Geographic Encoding and Referencing database with the final 2010 TEA Delineation results from January 30 through February 13, 2009.