CMS Part C & D Utilization Data: Encounters with Anomalies
Published on Sep 14, 2026 by Rebecca Vick
While CMS data systems systems perform validity checks, the final output still depends on the quality of the data from plans.
Understanding Chart Reviews in CMS Encounter Research Identifiable Files: Some Background and Descriptive Statistics
Background
Part C encounter RIF data includes two types of records: service records and chart reviews. Medicare Advantage Organizations (MAOs) perform retrospective reviews of their beneficiaries’ medical records to identify diagnoses that were not originally submitted by providers or were submitted in error. MAOs may report diagnosis changes identified because of these reviews to CMS as chart reviews; that is, MAOs use chart reviews to add or delete diagnoses to members’ records for the purpose of risk adjustment.
CMS Encounter Research Identifiable Files – How Are They Different from Fee-For-Service Files?
Encounter Research Identifiable Files: some differences compared to Fee-For-Services
The Centers for Medicare and Medicaid Services (CMS) collects service-level encounter data from Medicare Advantage Organizations (MAOs) for the purpose of recording diagnoses used for risk adjusted payments to MAOs(2). Unlike a fee-for-service (FFS) claim, an encounter record is not a direct record of payment and not used for billing purposes. Thus, Encounter Research Identifiable Files (RIFs) have some unique aspects to consider: