The population and housing unit estimates are released on a flow basis throughout each year. Each new series of estimates (referred to as a "vintage") is revised annually beginning with the date of the most recent decennial census to incorporate the latest administrative record data, geographic boundaries, and methodology.

The vintage year (e.g., V2023) refers to the final year of the time series. The reference date for all estimates is July 1, unless otherwise specified. Products are released for each new vintage between December and June. During these months, pages will show a combination of products from both the new vintage and the previous year's vintage. As new products are released, they supersede the older vintage products. We recommend that the most recent vintage available is used whenever possible. However, data from separate vintages should not be combined. To access past vintages of data, please see the FTP2 site.

Additional estimates files for some historical vintages may also be accessed via the Census Bureau application programming interface (API). Current estimates are unable to be supported by the API at this time.

Information on the Population and Housing Unit Estimates Special Tabulation Program.