Bipartisan leaders of a House panel are pressing the Census Bureau on the status of preparations the 2020 headcount, saying that recent briefings from GAO “heightened our initial concerns.”

The letter notes that the panel asked in November for information about the IT system deployment for the upcoming test, which it called “the final opportunity for Census to field test more than 40 key IT systems prior to the 2020 decennial census, most of which are new.”

The letter said the information has not been provided despite follow-up efforts at the staff level; it asked for an immediate response along with a briefing.

“According to GAO, not only are IT systems for the 2018 test delayed, many will not be properly tested prior to deployment and many key systems, such as fraud detection, will not be available at all during the live 2018 test beginning April 1,” said a letter from members including the chairman and ranking Democrat on the government operations subcommittee of the Oversight and Government Reform Committee.

The committee plans to hold hearings soon on the upcoming test.