This is redistricting data from the 2020 census at the census tract level. Technical documentation for the decennial census is available here: https://www.census.gov/programs-surveys/decennial-census/technical-documentation/complete-technical-documents.html

This is 2020 decennial census data at the place level. Technical documentation is available here: https://www2.census.gov/programs-surveys/decennial/2020/technical-documentation/complete-tech-docs/summary-file/2020Census_PL94_171Redistricting_NationalTechDoc.pdf

This is 2020 decennial census data at the county level. Technical documentation for the 2020 census is available here: https://www2.census.gov/programs-surveys/decennial/2020/technical-documentation/complete-tech-docs/summary-file/2020Census_PL94_171Redistricting_NationalTechDoc.pdf

Chris Briem of the University of Pittsburgh Center for Social and Urban Research has been producing extracts from the Census Bureau's PL 94-171 redistricting file. On August 12th, the U.S. Census Bureau released the first detailed data from the 2020 Decennial Census of Population and Housing. Before this, the only data that has been released from the 2020 Census has been total population counts by state needed for the reapportionment of congressional seats. The data just released is known as PL 94-171 data and includes the final census enumeration of the population by race and ethnicity for counties, municipalities, and smaller levels of geography. PL 94-171 data is used in the redrawing of the boundaries for federal, state, and local legislative districts, a process known as redistricting. This data includes housing unit counts, occupancy status for housing units, population totals, and population by race Hispanic/Latino origin, voting-age population (age 18+), and group quarters counts. The Census Bureau will be releasing additional data, including more detailed population and household statistics from the 2020 Census in the future.

Census 2020 Tracts with selected 1990, 2000, 2010, 2020 P.L. 94-171 redistricting data - includes a row for city totals.,

Community Reporting Areas with selected 1990, 2000, 2010, 2020 P.L. 94-171 redistricting data. This includes group quarters population (institutionalized/non) from the 1990, 2000 and 2010 summary file to be consistent with the available 2020 data.,

Overview of the Austin-Travis County Census 2020 effort.

Total Population of Regions, Counties, Towns, and Cities - 2010 and 2020