As NCI continues to evaluate the comparability of race data between cancer incidence and U.S. Census Bureau's population estimates and to explore reporting options, cancer incidence and mortality rate statistics released in April 2025 will continue to use bridged race categories.

The county bridged race population estimates currently used in the SEER*Stat software as the denominators for calculating cancer incidence and mortality rates are available for download (see Download U.S. Population Data). They represent modifications to the intercensal and postcensal Vintage 2023 annual time series of July 1 county population estimates by single year of age, sex, bridged race, and Hispanic origin.

Intercensal Estimates

Intercensal estimates used by NCI as denominators are typically produced by U.S. Census Bureau's Population Estimates Program once the decennial census at the end of the decade has been completed. However, Census Bureau delayed the production of 2010-2019 intercensal estimates. Starting in the NCI's April 2024 release, 2010-2019 intercensal estimates have been produced by Woods & Poole Economics, Inc. (W&P) through a contract with NCI. In the NCI's April 2025 release, W&P updated the previous estimates to incorporate the new April 2020 "blended base (PDF)" estimates used in producing Vintage 2023. To prepare for a smooth transition to use Census Bureau's intercensal population data in NCI's next release, the methodology used by W&P follows previously published Census methodologies to align closely with the anticipated Census Bureau's county intercensal estimates by demographic characteristics that are tentatively scheduled to be released in 2025. Detailed methodology is described in W&P's technical report (PDF, 282 KB).

Postcensal Vintage 2023 Estimates

Vintage 2023 population estimates are produced by U.S. Census Bureau through an Interagency Agreement with NCI. Vintage 2023 estimates are not significantly revised compared to Vintage 2022, however, there are revisions in population by age largely due to the incorporation of Hispanic origin data from the 2020 Census for the first time. For the U.S. total, population cohorts age 18-27 and age 75 and over are both revised downward approximately 3%, and other age cohorts are revised upward approximately 0.6% in Vintage 2023 compared to Vintage 2022. The revisions in county and census tract population by age may be greater in some instances. In addition, starting with Vintage 2022, nine planning regions are used as county-equivalent geographic units for reporting July 1 population estimates series for the state of Connecticut. To align with the geographic unit currently used for tracking cancer incidence and deaths, W&P converted 2020-2023 populations for Connecticut from planning regions to counties.

Modifications

Modifications made by NCI to W&P and Census Bureau estimates are documented in Modifications to the County Population Data and are summarized below.

  • The population estimates incorporate intercensal (for July 1, 2000-2009, July 1, 2010-2019) and Vintage 2023 (for July 1, 2020-2023) bridged race estimates that are derived from the original multiple race categories in the 2000, 2010 and 2020 Censuses. The bridged race estimates and a description of the methodology used to develop them appear on the National Center for Health Statistics website.
  • A modification that NCI has made to the Census Bureau estimates only affects population estimates for the state of Hawaii. Based on concerns that the native Hawaiian population has been vastly undercounted in previous censuses, the Epidemiology Program of the Hawaii Cancer Research CenterExternal Web Site Policy has recommended an adjustment to the populations for their state. The "Hawaii-adjustment" to the Census Bureau’s estimates has the net result of reducing the estimated white population and increasing the estimated Asian and Pacific Islander population for the state. The estimates for the total population, black population, and American Indian and Alaska Native populations in Hawaii are not modified.
  • Population estimates for 2005 are adjusted for population shifts due to hurricanes Katrina (August 29) and Rita (September 24). These estimates are lower for counties/parishes that had direct hurricane impact and higher for counties/parishes that were destinations for those displaced. See Adjusted Populations for the Counties/Parishes Affected by Hurricane Katrina and Rita for more information.

A further modification made by W&P to all intercensal and postcensal estimates (from July 1, 1969 to July 1, 2023) breaks age data for 85+ into single year of age up to 89 and 90+, for all combinations by county, sex, bridged race and Hispanic origin. For the first time, this new age data is used to calculate cancer rates adjusted using 20 age groups (with the additional 85-89 age group) in NCI's April 2025 release. This switch from 19 age groups to 20 age groups for age adjustment will result in different rates even in years where the numerators (case counts for incidence rates and death counts for mortality rates) remain unchanged, reflecting differential weights given to 84-89 age group and 90+ age group populations.

Single year of age population estimates by county are available on the Download U.S. Population Data page. The methods used to create these estimates are described in Single Year of Age County Population Estimates.

Standard Population Data Files containing age distributions used as weights to create age-adjusted statistics are also available.

Suggested Reference for Intercensal 2010-2019 Population Estimates: 2010 to 2019 Intercensal Estimates of County Population by Age, Sex, and Bridged Race for Vintage 2023 Postcensal Estimates, Woods & Poole Economics, Inc., Washington D.C. December 2024.

Note: The 1969-2022 U.S. Population Data will be available through May 15, 2025.