From the Document: "Press reports in May 2020 indicated that officials in the Trump Administration had discussed whether to conduct an explosive test of a U.S. nuclear weapon. The United States has observed a voluntary moratorium on nuclear explosive testing since 1992, although it has maintained the ability to resume these tests at the Nevada Nuclear Security Site (NNSS). Since 1993, it has used a program known as Science-Based Stockpile Stewardship to maintain confidence in the safety, security, and effectiveness of its nuclear arsenal."
CRS In Focus, IF11662
Congressional Research Service: https://crsreports.congress.gov/