Income variables for 5-year ACS data are not adjusted for inflation in the original PUMS data that the Census Bureau releases. IPUMS adjusts dollar amount variables in the multiyear ACS samples to report values in constant dollars, adjusted to the last year of the multiyear file. For example, we adjust dollar amount variables in the 2019-2023 5-year ACS sample into 2023 dollars.
The Census Bureau provides an inflation adjustment factor for users to manually adjust dollar amount values for inflation. The variable for the adjustment factor is called ADJINC in the original PUMS data. The value of ADJINC is constant within single-year ACS data files, and within each single year of multi-year ACS data files (i.e., within each value of MULTYEAR). This adjustment factor makes adjustments to account for the rolling survey schedule of the ACS. In the multiyear files, it also adjusts dollar values to the final year. Because IPUMS automatically adjusts multiyear files to report dollars to the final year value, our version of the ADJINC variable (ADJUST) provides only the component that adjusts for the rolling survey schedule. This means that the IPUMS variable ADJUST and the original Census Bureau PUMS variable ADJINC will not match in the multi-year files. Note also that the IPUMS adjustments for inflation in the multiyear files do not include the adjustment for the rolling data collection of the ACS. IPUMS does not adjust dollar amounts for inflation in single-year ACS files.
You can read more about the standardization of ACS/PRCS income variables and other dollar amount variables on this page from IPUMS.
The index used for annual adjustment, the Consumer Price Index research series using current methods (CPI-U-RS), comes from the Bureau of Labor Statistics. You can read more about this index and download a spreadsheet of average monthly and annual CPI-U-RS values on the BLS R-CPI-U-RS Homepage. Additionally, this CPI Research Series paper provides detailed information on how CPI-U-RS was constructed. Read more about inflation adjustment of multi-year samples starting on page 65 of the ACS Handbook.
This forum post was edited on June 25, 2026 because it previously included incorrect information.