ACS API not including all Counties

Hi all,

I am currently trying to create a county dataset containing demographic (specifically percentages of specific races) variables, so I am using the census API to try to expedite the process. I'm looking at the ACS 2021 response for DP05 for all counties and states, but when I make my CSV file of what the API gives me. I only have 834 counties, while there are 3,143 counties in the US. Is there any way I can change it to get all counties? Or are they better ways to achieve to get all the county info? This is what I currently have:*&in=state:*

Any advice would help.


  • Hello, 

    The ACS 1-year file is limited to counties with at least 65,000 people. For a complete set of counties you will need to use the ACS 5-year file (latest version covers the period from 2017-2021). 
    I hope this helps.


  • not all counties are in ACS one year — you could get every county for 2020 with race/Hispanic from PL94 data (downloadable from Nhgis )

  • FYI, just so you know I looked at the total population and ACS1 cover almost 85% of the total US population.  There are many fields and data points in ACS5 that are blank or removed due to the small set and privacy issues. So? You actually might get most of what you need from ACS1. In all the Census notes it states that ACS5 is better and more accurate. I think that may not be the case as so much has happened over the past few years and mixing in all the prior years (even with all the magic stats they do), that I have mixed feeling about using ACS5. Full Disclosure. This from someone who is new and not a stat person.