The U.S. Census Bureau begins planning for an upcoming decennial census of population and housing more than a decade prior to the census year. Part of this planning includes field tests designed to assess various operational features of the upcoming decennial census. For example, during the 2020 decennial census cycle, the Census Bureau conducted several small-scale tests beginning in 2013, as well as the major 2019 census test, which among other things addressed the effect of a proposed citizenship question on self-response rates. For the 2030 decennial census cycle, the Census Bureau has ongoing small-scale testing as well as a planned 2026 census test and 2028 dress rehearsal.

The Census Bureau began releasing initial plans for the 2026 census test in the spring of 2024 under the Biden Administration. The initial test sites as well as testing objectives were announced in July 2024. The Trump Administration released revised plans for the 2026 census test in February 2026, and released additional details in March 2026.

2026 Census Test Plan

On February 3, 2026, the Census Bureau released a Federal Register (FR) notice announcing plans for the 2026 operational test. The test will be conducted using the American Community Survey (ACS) Methods Panel, which will use the ACS questionnaire "to help the Census Bureau prepare for the 2030 Census." All questions from the ACS will be featured in the self-response portion of the test, according to supporting material. According to the Census Bureau, the questions "are expected to take around 40 minutes to complete and include name, race, sex, citizenship, and education."

The test will evaluate and assess the viability of using United States Postal Service (USPS) workers for in-field enumeration operations "to increase efficiency in various capacities typically performed by temporary Census Bureau field workers." Other in-field enumeration operations featured in the test include technical enhancements to mobile devices used by enumerators with the goal of streamlining data collection, reducing time in the field, and improving data accuracy. The Census Bureau previously considered a pilot for the 2018 end-to-end census test to use USPS letter carriers as Census Bureau enumerators, but ultimately did not undertake the pilot due to concerns about conflicting administrative processes within the two agencies.

Administrative enhancements focusing on evaluating processes relating to recruitment, office management, and payroll and human resources administration will also be a feature of the test.

The test will be conducted at selected areas within the metro areas of Spartanburg, SC, and Huntsville, AL. Supporting material for the FR notice indicates that the test will sample roughly 155,000 housing unit addresses and that group quarters are outside of the scope of the test. Housing units will initially be invited to respond using internet self-response, which will be available in English. Households that do not respond will be contacted in person during in-field enumeration.

Timeline

Activities for the 2026 census test were scheduled to begin in October 2025 and are scheduled to conclude in summer 2026, as seen in Table 1.

Original Plan

The February 2026 FR notice details a different plan for the 2026 census test than was originally announced in January 2025. The original plan was to use the 2020 decennial census questionnaire (rather than the ACS questionnaire) and include a nationally representative sample of households that could respond to the survey online, by phone, or by mail (rather than online only). The Census Bureau also dropped the planned test for group quarters enumeration, which has a different process from other enumeration. The original test was to include a bilingual (English and Spanish) paper questionnaire, instead of English only.

Originally, the Census Bureau selected six locations (including the two current sites) based on various criteria that the bureau indicated supported the test objectives, including an intent to focus on hard-to-count and historically undercounted populations.

Leading up to the 2020 decennial census, the Census Bureau had previously cancelled several test sites in 2017 due to funding uncertainty.

Issues for Congress

As the planned start of the 2026 census test draws near, a number of issues may be relevant for Congress's oversight and legislative responsibilities.

Plans for the current iteration of the test were released in February 2026 with additional information released in March. Members of Congress may consider requesting that the Census Bureau provide further information on the plans for the 2026 census test through documents or briefings.

Congress may consider conducting oversight on the planned USPS in-field enumeration pilot. This could include gaining a deeper understanding of the goals of the pilot as well as an assessment of its opportunities and risks.

Members may also have interest in better understanding the objectives and potential effects of focusing on the two current locations relative to the original six-location plan (which also was to include a nationally representative sample of households). Congress could request information from the Census Bureau on issues such as the budgetary costs and the utility of the data gathered under the two-location and six-location plans, respectively.

There may be congressional interest in the Census Bureau's plans related to several aspects of the response methods and questionnaire, including plans to collect only online self-responses rather than including telephone and mail responses; to offer the self-response option only in English; and to use the ACS questionnaire instead of the traditional decennial census questionnaire.

Finally, Congress may have an interest in the Census Bureau's updated timeline for the 2026 census test and when the results for the test will be made available, as well as in additional information about how the results from this test will inform further preparation for the 2030 census.