Medicare Advantage Compliance Audit of Specific Diagnosis Codes That Gateway Health Plan, Inc., (Contract H5932) Submitted to CMS

Issued on

03/12/2026

| Posted on

03/16/2026

| Report number: A-03-22-00004

Report Materials

• Full Report (PDF, 3.7 MB)
• Report Highlights (PDF, 349.5 KB)

Why OIG Did This Audit

• Under the Medicare Advantage (MA) program, CMS makes monthly payments to MA organizations based in part on the health status of the enrollees being covered.
• To determine the health status of enrollees, CMS relies on MA organizations to collect diagnosis codes from its providers and submit these codes to CMS. Some diagnoses are at higher risk for being miscoded, which may result in overpayments from CMS.
• This audit of Gateway Health Plan, Inc., is part of a series of audits in which we are reviewing high-risk diagnosis codes that MA organizations submitted to CMS for use in its risk adjustment program.

What OIG Found

Most of the selected diagnosis codes that Gateway submitted to CMS for use in CMS’s risk adjustment program did not comply with Federal requirements.

• For 232 of the 286 sampled enrollee-years, medical records did not support the diagnosis codes and resulted in $830,334 in net overpayments.
• On the basis of our sample results, we estimated that Gateway received at least $4.3 million in net overpayments for 2018 and 2019. As demonstrated by the errors found in our sample, Gateway’s policies and procedures to prevent, detect, and correct noncompliance with CMS’s program requirements, as mandated by Federal regulations, could be improved.

What OIG Recommends

We recommend that Gateway:

1. refund to the Federal Government the $4.3 million of estimated net overpayments;
2. identify, for the high-risk diagnoses included in this report, similar instances of noncompliance that occurred after our audit period and refund any resulting overpayments to the Federal Government; and
3. continue its examination of its existing compliance procedures to identify areas where improvements can be made to ensure that diagnosis codes that are at high risk for being miscoded comply with Federal requirements (when submitted to CMS for use in CMS’s risk adjustment program) and take the necessary steps to enhance those procedures. Gateway disagreed with some of our findings and all of our recommendations.

Report Type Audit HHS Agencies Centers for Medicare and Medicaid Services Issue Areas Contracts Financial Stewardship Managed Care Target Groups Elderly Financial Groups Medicare C

Notice

This report may be subject to section 5274 of the National Defense Authorization Act Fiscal Year 2023, 117 Pub. L. 263.