The Census Bureau assigned the 9400 range of numbers to identify specific tribal census tracts; however, not all tribal census tracts used this numbering scheme.

How are census tracts assigned?

Census Bureau identifies census tracts and BNAs by number rather than name. Each census tract has a basic census tract number composed of no more than four digits, and may have an optional two-digit decimal suffix. ... All BNAs have a four-digit basic number and may have an optional two-digit decimal suffix.

Who is responsible for conducting the census?

The U.S. Census Bureau is a principal agency of the U.S. Federal Statistical System that is responsible for conducting the national census at least once every 10 years.