Internal CMS contradiction: POS-certified providers also flagged NPPES-deactivated
Medicare Provider of Services (POS) says the facility is certified; NPPES says the provider is deactivated. Would be a federal data quality finding that should never be true — but **blocked on a join-key problem**. The POS files (data.cms.gov: iQIES, CLIA, Hospital_and_other) are CCN-keyed and do not carry an NPI column, so the NPPES-NPI × POS-certification join cannot be computed without a CCN ↔ NPI cross-walk. PECOS publishes a partial cross-walk for facility owners (which we touch in H35); a comprehensive CCN→NPI cross-walk for all certified facilities is the missing piece.
Null hypothesis
Zero NPPES-deactivated NPIs appear in the current Medicare Provider of Services file as actively certified.
Denominator
~260,551 NPPES-deactivated NPIs × every NPI appearing as actively certified in the latest POS quarterly release. Currently uncomputable — POS files are CCN-keyed and lack an NPI column.
Data source
NPPES × CMS POS Files (data.cms.gov, quarterly). Files identified: POS_File_iQIES_Q1_2026.csv (post-acute care, 77K rows, CCN-keyed); Hospital_and_other.DATA.Q1_2026.csv (hospitals etc., 473 columns, CCN-keyed); CLIA.DATA.Q1_2026.csv (labs). None carries an NPI column. Stage B = build CCN↔NPI cross-walk via PECOS owner data or an authorized CMS source.
Pre-registered — results not yet published.
This finding is listed here before results drop. That is the project's trust contract: the null hypothesis and the computation are public first, and numbers follow. Methodology: /methodology.