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Series: Nationwide Audits of Medicare Part C High-Risk Diagnosis Codes

Announced on  | Last Modified on  | Series Number: SRS-A-25-021
Status
Active
Agency
Centers for Medicare and Medicaid Services

OBJECTIVE

Payments to Medicare Advantage (MA) organizations are risk-adjusted on the basis of the health status of each enrollee. MA organizations are required to submit risk-adjustment data to CMS according to CMS instructions (42 CFR § 422.310(b)). Miscoded diagnoses may cause CMS to pay MA organizations improper amounts (The Act §§ 1853(a)). For these audits, we will focus on enrollees who received diagnoses that are at high risk for being miscoded and resulted in increased risk-adjusted payments from CMS to MA organizations. We will determine whether these diagnosis codes, as submitted by MA organizations to CMS for use in CMS's risk-adjustment program, complied with Federal requirements.

There are 2 projects in this series.

Project titles will remain unpublished until projects are complete and reports are posted.

ACTIVE PROJECTS IN THIS SERIES (1)

Project OAS-25-04-152 • Announced on Oct 7, 2025

COMPLETED PROJECTS IN THIS SERIES (1)

CMS Potentially Overpaid Medicare Advantage Organizations $462 Million Based on Certain Unsupported Acute Stroke Diagnosis Codes

Project A-02-23-01020 • Completed on May 28, 2026

TIMELINE

  • July 17, 2023
    Series Number SRS-A-25-021 Assigned
  • July 17, 2023
    Project Announced

    CMS Potentially Overpaid Medicare Advantage Organizations $462 Million Based on Certain Unsupported Acute Stroke Diagnosis Codes - A-02-23-01020

  • October 7, 2025
    Project Announced

    Project OAS-25-04-152

  • May 28, 2026
    Project Complete - A-02-23-01020

    CMS Potentially Overpaid Medicare Advantage Organizations $462 Million Based on Certain Unsupported Acute Stroke Diagnosis Codes complete. This audit resulted in 1 recommendation.

  • Today
    1 Audit In-Progress
  • Est FY2028
    Estimated Fiscal Year for Series Completion

1 REPORT PUBLISHED

CMS Potentially Overpaid Medicare Advantage Organizations $462 Million Based on Certain Unsupported Acute Stroke Diagnosis Codes (A-02-23-01020)

26-A-02-067.01 to CMS - Open Unimplemented
Update expected on 11/27/2026
We recommend that CMS implement a procedure to prevent overpayments to MA organizations when acute stroke diagnosis codes are submitted by MA organizations on a physician data record and the enrollee does not have an acute stroke diagnosis on an inpatient or outpatient hospital data record during the same service year (e.g., CMS filter of EDS data to identify and address these diagnosis codes or instructions to MA organizations to implement a control to prevent the submission of these diagnosis codes), which could have resulted in cost savings of $462 million.

View in Recommendation Tracker
Work Plan Type
Office of Audit Services
HHS Agencies
Centers for Medicare and Medicaid Services
Issue Areas
OIG Statutory Authority and Regulatory Matters Managed Care
Target Groups
-
Financial Groups
Medicare C