Clinical Trials by US State
Trial activity across all 52 US states and territories with registered ClinicalTrials.gov study sites.
Coverage: national, every US state and territory is included. A trial is counted in a state when it lists at least one study site there, so multi-site trials appear in more than one state.
According to ClinicalTrials.gov, the public registry maintained by the U.S. National Library of Medicine, 175,638 US clinical trials are recorded across 52 states and territories, with 24,857 currently recruiting. Research is heavily concentrated: California alone hosts 16,646 trials with study sites in-state, reflecting the location of major academic medical centers, cancer institutes, and pharmaceutical research hubs. Because a single multi-site trial is counted in every state where it has a recorded location, state totals overlap and should be read as a measure of local research access rather than a national sum. Select any state below for its phase mix, recruitment status, and the conditions and sponsors most active there. See our methodology for how state counts are derived.
Source: ClinicalTrials.gov (NIH/NLM) ClinicalTrials.gov AACT registry · 2026 State trial counts are derived from study-location records in ClinicalTrials.gov. A trial appears in every state where it lists a site.