Fraud Detection — claims screening → cited investigation

Screens a Medicare/Medicaid claims corpus against the public rulebook (NCCI MUE, OIG LEIE, CMS enrollment, PFS) and produces ranked, fully-cited investigation referrals for an SIU. The skill orchestrates a three-tier investigation: a deterministic floor does the detection, the model judges and narrates on top, and every dollar/rule allegation traces back to the floor.

Output framing

• "Indicators consistent with [scheme]," not "fraud." A pattern match doesn't establish intent — that's a downstream investigative/legal determination. This is standard SIU language and the framing the renderers use.
• Render for review. The skill writes packets to $CLAUDE_HEALTHCARE_DATA/fraud-detection/out/; the payer's SIU workflow decides what to do with them. The model does not send/publish on its own.

Inputs

• The payer's claims in corpus.duckdb (canonical 6-table schema: claims-schema.sql). Getting this is step 1 below — without it nothing else matters.
• Quarter (the NCCI/PFS rule set to cite against, e.g. 2026q3).
• Line of business (medicare / medicaid).