Census region view regions-v1. Four published SUMLEV 020 regions from retained PEP Vintage 2025 file NST-EST2025-ALLDATA.csv. All member-state/DC sums validated against published regional totals for every July 2020–2025 date. Fixed source snapshot pep-2025-r1; no mutation to the existing dataset archive. Census geography regional membership: https://www2.census.gov/geo/pdfs/maps-data/maps/reference/us_regdiv.pdf. Includes DC in South; excludes territories. Codes are text. Population universe: resident population. No survey margin supplied. Source attribution: U.S. Census Bureau.