American Community Survey
Location(s)4600 Silver Hill Road, Suitland, Maryland, U.S.
InauguratedJanuary 2005; 19 years ago (2005-01)
Participants3.5 million households/year

The American Community Survey (ACS) is an annual demographics survey program conducted by the U.S. Census Bureau. It regularly gathers information previously contained only in the long form of the decennial census, including ancestry, US citizenship status, educational attainment, income, language proficiency, migration, disability, employment, and housing characteristics. These data are used by many public-sector, private-sector, and not-for-profit stakeholders to allocate funding, track shifting demographics, plan for emergencies, and learn about local communities.[1]

Sent to approximately 295,000 addresses monthly, or 3.5 million addresses annually, it is the largest household survey that the Census Bureau administers.[2]

The American Community Survey gathers information annually in the 50 U.S. states, the national capital of Washington, D.C., and (via the Puerto Rico Community Survey (PRCS), which is part of the ACS) Puerto Rico.[a] It does not gather information in the other four major U.S. territories of American Samoa, Guam, Northern Mariana Islands, and the U.S. Virgin Islands.[5][6]


The United States Constitution (Article I, Section II) requires an enumeration of the population every ten years "in such Manner as they (Congress) shall by Law direct". From the first census in 1790, legislators understood that it should collect basic demographic information beyond the number of people in the household. James Madison, a Founding Father and the fourth President of the United States, first proposed including questions in the census to "enable them to adapt the public measures to the particular circumstances of the community". Such knowledge collected with each census, Madison argued, "would give them an opportunity of marking the progress of the society".[7] The questions included in censuses since 1790 have reflected American understandings of and concerns about societal trends and the growing nation's expanded data needs.[8]

By 1940, advancements in statistical methods enabled the U.S. Census Bureau to begin asking a sample of the population a subset of additional detailed questions without unduly increasing cost or respondent burden.[9] In the decades that followed, new questions were added to those that had previously been asked of all respondents, and all the questions were moved to the sample questionnaire form. As the sample form grew longer than the census form itself, it became known as the census "long form".

Following the 1960 Census, federal, state, and local government officials, and some in the private sector began demanding more timely long-form-type data. Lawmakers representing rural districts claimed they were at a data disadvantage, unable to self-fund additional surveys of their populations.[10][11] Congress explored the creation of a mid-decade census, holding hearings and even authorizing a mid-decade census in 1976, but not funding it.[12][13][14]

Efforts to obtain data on a more frequent basis began again after the 1990 census, when it became clear that the more burdensome long form was depressing overall census response rates and jeopardizing the accuracy of the count. At Congress's request, the Census Bureau developed and tested a new design to obtain long-form data. U.S. statistician Leslie Kish had introduced the concept of a rolling sample (or continuous measurement) design in 1981.[15] This design featured ongoing, monthly data collection aggregated on a yearly basis, enabling annual data releases. By combining multiple years of this data, the Census Bureau could release "period" estimates to produce estimates for smaller areas. After a decade of testing, it launched as the American Community Survey in 2005, replacing the once-a-decade census long form.[16][17]


The American Community Survey's initially sampled approximately 3.5 million housing unit addresses and group quarters in the United States. The Census Bureau selects a random sample of addresses to be included in the ACS. Each address has about a 1-in-480 chance of being selected in a given month, and no address should be selected more than once every five years. Data is collected by internet, mail, telephone interviews, and in-person interviews. The questionnaire is available in English and Spanish,[18] with assistance provided in additional languages.[19] Approximately one-third of those who do not respond to the survey by mail or telephone are randomly selected for in-person interviews. About 95 percent of households across all response modes ultimately participate in the survey.[20]

Like the decennial census, ACS responses are confidential. Every employee at the Census Bureau takes an oath of nondisclosure and is sworn for life to not disclose identifying information. Violations of the nondisclosure oath are punishable for prison sentences up to five years and/or a $250,000 fine.[21] Under 13 U.S.C. § 9, census responses are "immune from legal process" and may not "be admitted as evidence or used for any purpose in any action, suit, or other judicial or administrative proceeding".

Data availability

An American Community Survey data table sample

The Census Bureau aggregates individual ACS responses, also known as microdata, into estimates at many geographic summary levels. Among these summary levels are legal and administrative entities such as states, counties, cities, and congressional districts, as well as statistical entities such as metropolitan statistical areas, tracts, block groups, and census designated places. Estimates for census blocks are not available from ACS.[22] Puerto Rico is the only U.S. territory that is part of the ACS program.[6]

In order to balance geographic resolution, temporal frequency, statistical significance, and respondent privacy, ACS estimates released each year are aggregated from responses received in the previous calendar year or previous five calendar years. The Census Bureau provides guidance for data users about which data set to use when analyzing different population and geography sizes.[23]

From 2007 to 2013, three-year estimates were available for areas with 20,000 people or more. This data product was discontinued in 2015 due to budget cuts.[24] The last 3-year release was the 2011–2013 ACS 3-year estimates.

Current data releases include:

Over the past decade, the American Community Survey has collected and supplied all data at local levels. This was a large breakthrough in the survey because it allows American citizens more individualized data on a community level as opposed to extrapolating from data collected over a larger area. It has also provided unparalleled information to be more accessible for local government planning and financing. Many conclusions for local data are averaged from various information across the area, but it is not always an adequate representation.[26]

ACS estimates are available via a number of online data tools.[27] U.S. Census website (AFF) is the primary tool for disseminating ACS data, allowing users to drill down to specific tables and geographies (starting with 2013 estimates, AFF also includes block group data). A selection of the most popular tables is shown in QuickFacts. Other tools include OnTheMap for Emergency Management, Census Business Builder and My Congressional District. My Tribal Area featuring 5-year estimates for federally recognized tribes, launched in 2017. The Summary File is the most detailed data source, and is available as a series of downloadable text files or through an application programming interface (API) for software developers.

Custom cross-tabulations of ACS questions can be made using the Public Use Microdata Sample (PUMS), freely accessible through the Census Bureau website and Integrated Public Use Microdata Series. PUMS data contain responses to every question from a sample of respondents. To protect respondent privacy, PUMS data are anonymized and only available down to areas containing 100,000 people or more known as Public Use Microdata Areas (PUMAs).[28] The analysis of all ACS microdata without the sampling and anonymization in PUMS is restricted to qualified researchers at secure Federal Statistical Research Data Centers (FSRDCs).[29]

Research studies

The Census Bureau conducts research and evaluation projects, including survey methodology research, important for the improvement of the ACS.[30][31][19]

The ACS data is used by researchers to examine societal changes, to study data quality, and to conduct methodological research.[32][33]



American Community Survey data provides important information that cannot be found elsewhere. The federal government, as well as various businesses, researchers, and local governments use ACS data for planning and decision-making purposes. ACS data are used by public and business decision-makers to more clearly identify issues and opportunities and more effectively allocate scarce resources to address them.[34][35][36] In Fiscal Year 2008, 184 federal domestic assistance programs used ACS-related datasets to help guide the distribution of $416 billion, 29 percent of all federal assistance.[37]

The American Community Survey is authorized by 13 U.S.C. § 141 and 13 U.S.C. § 193.[38] Federal courts have held that the long form is constitutional.

In 2000, the U.S. District Court for the Southern District of Texas ruled that the 2000 U.S. census and its questions did not violate the Fourth Amendment or other constitutional provisions that were alleged in the federal lawsuit initiated by the plaintiffs. The court said responses to census questions are not a violation of a citizen's right to privacy or speech.[39]

The U.S. District Court's decision was later affirmed by the United States Court of Appeals for the Fifth Circuit on appeal, and the U.S. Supreme Court denied petition for writ of certiorari.[40] A number of other courts, including the U.S. Supreme Court, have held through the years that the census and the questions in the census are authorized by both the Constitution and statute.[41]

In 2002, the General Accounting Office confirmed that the Census Bureau has authority to conduct the survey and "require responses from the public". All individual American Community Survey responses are kept private and are used (along with other ACS responses) to create estimates of demographic characteristics for various geographies. Because of data swapping techniques to ensure confidentiality, it is impossible to figure out how individual people responded based on data from published ACS estimates.[38]


Opponents of the American Community Survey disagree with the court's findings about its constitutionality, contending that the survey asks for more information and at a higher frequency than the simple enumeration authorized and required by Article 1, Section 2 of the U.S. Constitution. Despite the Government Accountability Office's conclusion that the Census Bureau has the authority to conduct the survey under 13 U.S.C. § 141 and 13 U.S.C. § 193, several U.S. representatives have challenged the ACS as unauthorized by the Census Act and a violation of the Right to Financial Privacy Act. Rep. Ron Paul of Texas, who opposes ACS, said that the founding fathers of the United States "never authorized the federal government to continuously survey the American people".[42]

Those who decline to complete the survey may receive visits to their homes from Census Bureau personnel. Because it is a mandatory survey, it is governed by federal laws that could impose a fine of as much as $5,000 on those who flagrantly refuse to participate.

To date, no person has been prosecuted for refusing to answer the ACS.[43] Kenneth Prewitt, the former director of the Census Bureau, said in March 2000 that the U.S. Department of Commerce is "not an enforcement agency" and that the Department of Justice would be responsible for prosecuting violations, adding that "we don't recommend that".[44] The Census Bureau prefers to gain cooperation by convincing respondents of the importance of participation, while acknowledging that the mandate improves response rates (and thus accuracy) and lowers the annual cost of survey administration by more than $90 million.[45]

In 2014, the Census Project, a collaboration of pro-Census business and industry associations, gathered signatures from 96 national and local organizations urging the US House Committee on Oversight and Government Reform to reject a proposal to make the American Community Survey voluntary.[46] Signers included the US Chamber of Commerce, the National Association of Realtors and the US Conference of Mayors. The letter cited results from a congressionally mandated test of a voluntary ACS that found that mail response rates would drop "dramatically," by more than 20 percentage points.[47] The resulting loss in quality and reliability would essentially eliminate data for 41 percent of U.S. counties, small cities, towns and villages, many school districts, neighborhoods, remote areas, and American Indian reservations.[48]

See also


  1. ^ The US Census has a separate form for Puerto Rico called the Puerto Rico Community Survey, (PRCS). Despite the different form, the U.S. Census Bureau website states that "The PRCS is part of the ACS".[3] A question linking the PCRS with the ACS is if the respondent lived in Puerto Rico should they respond that they have resided in their current residence in the CONUS (or Alaska or Hawaii) for one year or less. The questions asked are different from the questions in the ACS.[4]


  1. ^ Eberstadt, Nicholas; Nunn, Ryan; Schanzenbach, Diane W.; Strain, Michael. In Order That They Might Rest Their Arguments on Facts: The Vital Role of Government-Collected Data.
  2. ^ US Census Bureau. "ACS Information Guide". p. 8. Retrieved July 31, 2015.
  3. ^ "American Community Survey Resources for Puerto Rico". U.S. Census Bureau. Retrieved May 13, 2024.
  4. ^ About the Puerto Rico Community Survey. Accessed 18 October 2020.
  5. ^ Frequently Asked Questions to Accompany the Estimates of at Least the Top 15 Languages Spoken by Individuals with Limited English Proficiency under Section 1557 of the Affordable Care Act (ACA). U.S. Department of Health and Human Services, Office for Civil Rights (OCR). Page 2. Retrieved August 30, 2019.
  6. ^ a b U.S. Census Bureau. An Overview Of the American Community Survey. Page 5. Retrieved August 30, 2019.
  7. ^ "The Founder's Constitution". The University of Chicago Press. Retrieved June 19, 2017.
  8. ^ U.S. Census Bureau. "Through The Decades: Index of Questions". Retrieved June 19, 2017.
  9. ^ U.S. Census Bureau. "1940 (Population) – History – U.S. Census Bureau". Retrieved June 19, 2017.
  10. ^ "The American Community Survey: A Replacement for the Long Form? United States House Subcommittee on the Census of the Committee of Government Reform, 106th Congress (2000)" (PDF). Library of Congress. Retrieved June 19, 2017.
  11. ^ "Mid-Decade Census, Part 1: Hearings before the Subcommittee on Census and Statistics, 87th Congress (1961)". Retrieved June 19, 2017.
  12. ^ "Mid-Decade Census: Hearings before the United States House Subcommittee on Census and Statistics of the Committee on Post Office and Civil Service, 89th Congress (1965)". Retrieved June 19, 2017.
  13. ^ "Mid-Decade Census: Hearings before the United States House Subcommittee on Census and Statistics of the Committee on Post Office and Civil Service, 92nd Congress, first session on proposals for a mid-decade census of population and housing (1971)". Retrieved June 19, 2017.
  14. ^ "13 U.S.C. 141(d)". Retrieved June 19, 2017.
  15. ^ Alexander, Charles. "Still Rolling: Leslie Kish's Rolling Samples and the American Community Survey" (PDF). U.S. Census Bureau. Retrieved June 19, 2017.
  16. ^ US Census Bureau. "American Community Survey: Design and Methodology (PDF) p. 2-1" (PDF). Retrieved June 19, 2017.
  17. ^ "ACS Design and Methodology. Chapter 2: Program History" (PDF). U.S. Census Bureau. Retrieved June 19, 2017.
  18. ^ "Sample ACS & PRCS Forms and Instructions". Retrieved November 29, 2023.
  19. ^ a b Sha, Mandy. "American Community Survey Language Assistance Guides in Multiple Languages". US Census Bureau. Retrieved November 29, 2023.
  20. ^ US Census Bureau. "Response Rates". Retrieved May 19, 2017.
  21. ^ US Census Bureau. "Is My Privacy Protected?". Retrieved July 31, 2015.
  22. ^ a b c US Census Bureau. "Areas Published". Retrieved July 31, 2015.
  23. ^ U.S. Census Bureau. "When to Use 1-Year, 3-Year or 5-Year Data". Retrieved May 24, 2017.
  24. ^ Poole, Ken. "The ACS 3-year Demographic Estimates Are History". APDU: The Association of Public Data Users. Retrieved July 31, 2015.
  25. ^ US Census Bureau. "American Community Survey Supplemental Data". Retrieved May 24, 2017.
  26. ^ Spielman, Seth; Singleton, Alex (September 3, 2015). "Studying Neighborhoods Using Uncertain Data from the American Community Survey: A Contextual Approach". Annals of the Association of American Geographers. 105 (5): 1003–1025. doi:10.1080/00045608.2015.1052335.
  27. ^ US Census Bureau. "Data Tools Chart". Retrieved July 31, 2015.
  28. ^ US Census Bureau. "About PUMS". Retrieved July 31, 2015.
  29. ^ US Census Bureau. "Federal Statistical Research Data Centers". Retrieved August 11, 2015.
  30. ^ "ACS Research & Evaluation Program". Retrieved December 18, 2023.
  31. ^ "Content Test Evaluation Reports". Retrieved December 18, 2023.
  32. ^ "The Modern American Family". Pew Research Center’s Social & Demographic Trends Project. September 14, 2023. Retrieved December 18, 2023.
  33. ^ Smalley, Heather (April 30, 2020). "A longitudinal perspective on the effects of household language on data quality in the American Community Survey (Chapter 3)". In Sha, Mandy (ed.). The Essential Role of Language in Survey Research. RTI Press. pp. 47–74. doi:10.3768/rtipress.bk.0023.2004. ISBN 978-1-934831-24-3.
  34. ^ Census Project. "Letter to Senate Committee on Appropriations Subcommittee on Commerce, Science, Justice and Related Agencies 3/17/16" (PDF). Retrieved August 7, 2017.
  35. ^ American Economic Association. "The American Community Survey is Essential" (PDF). Retrieved August 7, 2017.
  36. ^ National Retail Federation. "The Greatest Survey You've Never Heard Of". Archived from the original on August 8, 2017. Retrieved August 7, 2017.
  37. ^ Brookings Institution. "Surveying for Dollars: the Role of the American Community Survey in the Geographic Distribution of Federal Funds". Retrieved July 14, 2017.
  38. ^ a b US Government Accountability Office. "U.S. GAO – Legal Authority for American Community Survey, B-289852".
  39. ^ Morales v. Daley, 116 F. Supp. 2d 801, 820 (S.D. Tex. 2000) " . . . [I]t is clear that the degree to which these questions intrude upon an individual's privacy is limited, given the methods used to collect the census data and the statutory assurance that the answers and attribution to an individual will remain confidential. The degree to which the information is needed for the promotion of legitimate governmental interests has been found to be significant. A census of the type of 2000 census has been taken every ten years since the first census in 1790. Such a census has been thought to be necessary for over two hundred years. There is no basis for holding that it is not necessary in the year 2000."
  40. ^ The U.S. Court of Appeals for the Fifth Circuit affirmed the District Court decision on October 10, 2001, 275 F.3d 45. The U.S. Supreme Court denied petition for writ of certiorari on February 19, 2002, 534 U.S. 1135. No published opinions were filed with these rulings.
  41. ^ As early as 1870, the Supreme Court characterized as unquestionable the power of Congress to require both an enumeration and the collection of statistics in the census. The Legal Tender Cases, Tex.1870; 12 Wall., U.S., 457, 536, 20 L.Ed. 287. In 1901, a district court said the Constitution's census clause (Art. 1, Sec. 2, Clause 3) is not limited to a count of the population and "does not prohibit the gathering of other statistics, if 'necessary and proper,' for the intelligent exercise of other powers enumerated in the constitution, and in such case there could be no objection to acquiring this information through the same machinery by which the population is enumerated". United States v. Moriarity, 106 F. 886, 891 (S.D.N.Y.1901). All of these decisions are consistent with the Supreme Court's recent description of the census as the "linchpin of the federal statistical system ... collecting data on the characteristics of individuals, households, and housing units throughout the country". Dept. of Commerce v. U.S. House of Representatives, 525 U.S. 316, 341 (1999).
  42. ^ "None of Your Business!" by Ron Paul
  43. ^ Selby, W. Gardner. "Americans must answer U.S. Census Bureau survey by law, though agency hasn't prosecuted since 1970". Retrieved July 31, 2015.
  44. ^ US Census Bureau. "Census Bureau, Census 2000, Director Prewitt press briefing on March 30, 2000". Retrieved July 31, 2015.
  45. ^ US Census Bureau. "Mandatory vs. Voluntary Methods". Retrieved July 31, 2015.
  46. ^ The Census Project. "Letter to House Oversight and Government Reform Committee" (PDF). Retrieved July 14, 2017.
  47. ^ Navarro, Alfredo; King, Karen E.; Starsinc, Michael. "Comparison of the American Community Survey Voluntary Versus Mandatory Estimates". U.S. Census Bureau. Retrieved July 14, 2017.
  48. ^ The Census Project. "Letter to House Oversight and Government Reform Committee" (PDF). Retrieved July 14, 2017.