How "first licensed" is derived
Three chained public sources. No PHI.
1 · CredentialStream
Provider roster + NPI + primary office (cs_mirror.db, Abby's sync).
2 · NPI Registry API
npiregistry.cms.hhs.gov → enumeration date + license # + state (primary taxonomy).
3 · State Dental Board
License # + state → board verification portal → original issue date = first licensed.
Why NPI enumeration date ≠ first licensed. The NPI system opened in 2005–06, so almost every provider licensed before then shows a ~2006 enumeration date regardless of true licensure year. Example: Guy Gross, DDS — licensed in KS 2002-05-31, but NPI enumerated 2006-08-11. The state board is the only authoritative source for the real first-licensure date.
Coverage status. All 35 license states were scraped. 33 boards are live — 514 of 527 first-licensed dates pulled, each carrying the board's own literal date string as evidence. CAPTCHA-walled boards (GA, MS, CA, SC, UT, TN, MD) were unlocked via a paid 2Captcha solver or via residential-browser manual entry (UT, TN). Two boards remain effectively blocked: CT exposes no original-issue field (only renewal grant date), and OK's four are not on its public active-dentist list. No national source exists — every board is a separate portal (ASP.NET, Salesforce/Angular SPAs, Accela, Thentia, GLSuite, MyLicense, state open-data APIs), so each live board is its own adapter under scripts/adapters/.
⚠ Known limitation — multi-state careers. The pipeline pulls the doctor's primary license state from NPI Registry, then asks only that state's board for the original issue date. If a doctor practiced for 20 years in Colorado, then moved to New Mexico and now flags New Mexico as their NPI primary, this dashboard will report them as first licensed in 2024 — understating their actual clinical tenure by 19 years. 60 of 538 providers (11%) hold licenses in more than one state per their NPI taxonomy records, so this risk is real and measurable. The fix is to fan the lookup across every state on the NPI record and take the earliest date; that work is not yet built. For now, treat the "First Licensed" column as "first licensed in the state currently flagged primary on NPI" — a near-true floor for most, but a possibly significant understatement for any provider who has practiced in multiple states. The pillar is still useful (it filters out the NPI-enumeration-date noise) but should not yet be used to score career tenure for senior providers without manual review.
Anti-fabrication guarantee. A wrong licensure date is worse than a blank in a credentialing file. Every shown date was parsed from the board's actual HTTP response and is stored with the literal board string + source URL; the aggregator drops any date lacking that evidence. Blocked or absent providers are shown blank, never guessed — and the NPI enumeration date is never used as a stand-in.