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2020 PUMA Geography Update

The Tennessee State Data Center is tasked with leading the update to the state’s PUMA boundaries and will be seeking input from Census microdata users. Researchers, planners and other data users will be asked to weigh in with feedback on suggested boundaries.

Public Use Microdata Areas (PUMAs) are statistical boundaries used in conjunction with the Public Use Microdata Samples (PUMS) products published by the United States Census Bureau. The PUMA boundaries will be updated following the release of 2020 Census data to ensure they meet standards that protect the confidentiality of individual microdata responses.

Tennessee 2020 Final PUMA Boundary

Final Proposal Posted 2/7/2022

Tennessee’s final PUMA proposal was submitted to the Census Bureau on January 31, 2022 for review. User feedback overwhelmingly supported Alternative 2 which sought to better adhere to Census Bureau guidance and maximize the number of PUMAs in the state.

Tennessee 2020 Draft PUMA Boundaries

Draft Alternatives 1 and 2 Posted 12/21/2021

Tennessee final PUMA boundaries must be submitted to the Census Bureau by January 31, 2022. In advance of this deadline, the State Data Center has prepared two draft alternatives for data users to review and provide comment. Feedback on the drafts will be accepted through January 24, 2022.

2020 PUMA Criteria

Final Criteria Now Available

The Census Bureau posted final criteria, participant materials, data and software to the Census Bureau website that will be used throughout the PUMA update process. The criteria document details rules that we will govern Public Use Microdata Areas (PUMAs) changes based on results from the 2020 Census.

U.S. Census Bureau PUMA Update Program

PUMAs and PUMS data are related U.S. Census Bureau products used in conjunction with the decennial census and American Community Survey. You can learn more about the program, read Federal Register notices and draft proposals on the 2020 Public Use Microdata Areas (PUMA) Program website.

Date Activity
February 8, 2021 – April 30, 2021 Proposed 2020 PUMA criteria posted to Census Bureau website for comments. The comment period ends on April 30, 2021.
Spring 2021 U.S. Census Bureau publishes 30-day notice to the Federal Register for comment and concurrently submits final package for review
September 2021 State Data Centers notified of final criteria and participant materials shared
Fall 2021 Census Bureau conducts training for participating State Data Centers
November 2021 – January 2022 90-day review period for State Data Centers to delineate and submit PUMAs
Summer 2022 Final 2020 PUMAs and their associated 2020 data available online for use

Frequently Asked Questions

Public Use Microdata Areas, or PUMAs, are non-overlapping, statistical geographic areas that partition each state into geographic areas containing no fewer than 100,000 people each. They primarily follow county and census tract boundaries. Public Use Microdata Samples (PUMS) that coincide with these statistical areas are released, including the American Community Survey and the decennial census.

The Census Bureau provides resources to help data users learn more about PUMS including a recorded webinar hosted on March 11, 2020 and a handbook which provides an introduction PUMS data including how the data are organized and can be accessed.

State Data Centers (SDCs) define PUMAs with the cooperation of regional, state, local and tribal governments; organizations; and other interested data users. In Tennessee, the State Data Center is housed at the Boyd Center for Business and Economic Research at the University of Tennessee. In conjunction with the Greater Nashville Regional Council, the State Data Center will lead a process to engage the state’s data users to collect input on the proposed boundary changes.

More information about outreach will be made available in fall 2021 following the U.S. Census Bureau’s release of participant materials and training.

Most PUMA boundaries don’t need to be updated and often are preserved to facilitate comparisons over time. However, some areas will need to be revisited including:

  • Identifying PUMAs with more than 200,000 people that can be split into separate areas with at least 100,000 people while meeting other PUMA delineation criteria
  • Existing PUMA boundaries falling below the 100,000 person minimum population thresholds
  • Areas where portions of PUMAs cross county lines and contain fewer than 10,000 people

Many of the key elements of the PUMA boundary delineation are unchanged, meaning most areas within the state should remain unchanged. However two new criteria to help maintain the anonymity of the microdata survey responses have been introduced.

  1. Where PUMAs cross a county boundary, each county part must have a minimum population of 10,000 people
  2. PUMAs may include non-contiguous areas to more fully encompass areas with homogenous population but the each non-contiguous part must have a minimum population of 10,000 people

The Public Microdata Use Sample (PUMS) and the associated PUMA geography are anonymized single-person and single-household responses to the 2020 Census and  American Community Survey (ACS) questions. They are used in advanced analysis to construct custom tabulations that are not provided thought pre-compiled tables available

ACS PUMS data can be downloaded and analyzed using statistical software or through the web-based Microdata Access Tool.


The State Data Center is collaborating with the Greater Nashville Regional Council to conduct the 2020 PUMA geography update. Please direct questions or feedback to:

Tim Kuhn
Director, Tennessee State Date Center
Boyd Center for Business and Economic Research, Haslam College of Business
The University of Tennessee, Knoxville
(865) 974-6070

Max Baker
Director of Research and Analytics
Greater Nashville Regional Council
(615) 862-8728