How do 340B Medicaid exclusion files prevent duplicate discounts in fee-for-service billing?

340B Medicaid exclusion files help prevent duplicate discounts by signaling a covered entity’s carve-in or carve-out billing approach and linking it to the Medicaid identifiers used on fee-for-service claims. But the article stresses the file is only one control point; accurate claim edits, identifier tables, accumulator logic, and billing builds must also align.