generated: '2026-09-06'
method: searched
source: https://clinicaltrials.gov/about-site/release-notes
docs: https://clinicaltrials.gov/about-site/release-notes
news: https://clinicaltrials.gov/about-site/news-and-updates
scheme: dated-release-notes
current_version: 2.0.5
current_version_source: 'https://clinicaltrials.gov/api/v2/version (live probe 2026-09-06)'
cadence: irregular; roughly quarterly site releases, with API items called out under an "API" heading
coverage_note: >-
  The release-notes page carries 97 dated entries reaching back to 1998. Only the API-relevant
  and recent site entries are structured below. The page is a client-rendered Angular route,
  so the entries were read from the application's own release-notes content bundle
  (chunk-BMYXEWAI.js served from clinicaltrials.gov), not from a feed — there is no RSS or
  JSON changelog.
entries:
- date: '2026-06-09'
  version: null
  breaking: false
  additions: true
  highlights:
  - New patient/caregiver resources (Common Questions, How to Join a Study) under Find Studies.
  - New Demonstration Videos page; one outdated video removed.
  - Content refreshed for How to Search for Clinical Studies and How to Read a Study Record.
  api_affecting: false
- date: '2026-03-18'
  version: null
  breaking: false
  additions: true
  highlights:
  - 'Studies by Topic view gained Sponsors/Collaborators, Conditions and Interventions/Treatment groupings.'
  - Search Details bar now groups terms and synonyms by search area.
  api_affecting: false
- date: '2026-01-22'
  version: null
  breaking: false
  additions: true
  highlights:
  - "The Results Submitted filter can now be applied to the /studies API endpoint via the 'ressub' aggregate filter in the aggFilters field."
  - Glossary gained an alphabetical navigation bar and a site-wide slide-out drawer.
  api_affecting: true
- date: '2025-11-20'
  version: null
  breaking: false
  additions: true
  highlights:
  - Map View gained country/state/city hover counts and clickable Show Studies by Region rollups.
  api_affecting: false
- date: '2025-09-25'
  version: null
  breaking: false
  additions: true
  highlights:
  - Interactive Map View added to the Search Results page.
  - Search Details now reports per-page and total counts including synonym matches.
  api_affecting: false
- date: '2025-04-15'
  version: null
  breaking: false
  additions: true
  highlights:
  - Expert Search now generates a search expression from the basic search form.
  api_affecting: false
- date: '2024-04-30'
  version: 2.0.2
  breaking: false
  additions: true
  highlights:
  - Changed API version to 2.0.2.
  - GET /studies/{NCTId} now supports redirects to a study record based on NCTIdAlias.
  - Study Data Structure — Source Type and Source XPath renamed Classic Type and Classic XPath.
  - API documentation gained content about the schedule of data updates.
  api_affecting: true
- date: '2024-03-19'
  version: 2.0.1
  breaking: false
  additions: true
  highlights:
  - Changed API version to 2.0.1.
  - API Migration Guide updated to reflect legacy API endpoint support.
  - 'Announcement: the v2 API differs from the classic API in several important ways; classic API users strongly encouraged to migrate, with the classic API to be retired in June 2024.'
  api_affecting: true
- date: '2024-02-06'
  version: '2.0'
  breaking: true
  additions: true
  highlights:
  - First functional release of the ClinicalTrials.gov Data API v2.
  - API Migration Guide published for classic-API consumers.
  api_affecting: true
  note: >-
    The v2 release is the breaking change in this API's history — the classic API was retired
    in June 2024 and its paths now return HTTP 404. See lifecycle/clinical-trials-gov-lifecycle.yml.
unlisted_versions:
  note: >-
    Release notes stop calling out API version bumps after 2.0.2, but the live /version
    endpoint reports 2.0.5. Versions 2.0.3, 2.0.4 and 2.0.5 shipped without a dated
    release-note entry, so no consumer-readable record of what changed in them exists.