in a post on the Federal Data Users forum, Mark Mather of the Population Reference Bureau noted:

The Census Bureau is requesting public comment on its 2026 Operational Test in support of the 2030 Census. Three elements of the proposed test seem particularly relevant for federal data users:

• The Operational Test described in the notice is limited to two sites: Spartanburg, SC and Huntsville, AL. This is a narrower scope than earlier Census Bureau planning materials. In July 2024, the Bureau announced six planned 2026 test sites, selected to reflect a wide range of enumeration environments, including Tribal lands and rural areas.
• The notice also proposes testing the use of USPS employees as census enumerators. Under the proposal, U.S. Postal Service staff would conduct in-person census interviews in the same manner as Census Bureau field staff. This represents a notable operational change and raises questions about training, respondent interaction, and whether results from a limited test environment can be generalized nationally.
• The notice specifies that Internet Self-Response (ISR) for the test will be available only in English.

The Federal Register announcement of the comment request is available at this link. The comment period ends March 5, 2026.