News: Three OIG audits reveal gaps in Medicare Advantage diagnosis coding

Three newly released compliance audits from the U.S. Department of Health and Human Services Office of Inspector General (OIG) highlight significant gaps between high-risk diagnosis codes submitted for Medicare Advantage risk adjustment and the medical records supporting those diagnoses. The three reports are part of an OIG series reviewing whether documentation supports high-risk diagnosis codes.

Across the three organizations, the OIG found that 533 of 700 sampled enrollee-years lacked sufficient medical-record support for certain submitted diagnosis codes and estimated approximately $202.2 million in overpayments.

The audits examined selected high-risk diagnosis codes submitted to CMS for payment years 2020 and 2021. The organizations reviewed were UnitedHealthcare Benefits of Texas, Inc.; UnitedHealthcare of Wisconsin, Inc.; and HumanaChoice.

The term “enrollee-year” is used by the OIG to refer to an individual associated with a particular condition and payment year. An enrollee may therefore account for more than one enrollee-year if the individual had multiple high-risk conditions or the same condition was documented in more than one year.

The audit findings were as follows:

• UnitedHealthcare Benefits of Texas, Inc.: The OIG reviewed 230 enrollee-years, of which 172 lacked sufficient medical-record support. The sampled overpayments totaled $622,927, and the OIG estimated at least $24.4 million in overpayments for payment years 2020 and 2021.
• UnitedHealthcare of Wisconsin, Inc.: The OIG reviewed 250 enrollee-years, with 183 lacking sufficient medical-record support. The sampled overpayments totaled $722,280, and the OIG estimated at least $46.9 million in overpayments for payment years 2020 and 2021.
• HumanaChoice: The OIG reviewed 220 enrollee-years, of which 178 lacked sufficient medical-record support. The resulting sampled overpayments totaled $669,237, and the OIG estimated at least $130.9 million in overpayments for payment years 2020 and 2021.

The audits examined diagnosis codes associated with:

• Acute stroke
• Acute myocardial infarction
• Sepsis
• Embolism
• Lung cancer
• Breast cancer
• Colon cancer
• Ovarian cancer
• Prostate cancer
• Pressure ulcers

The sample-level error rates were substantial for several diagnosis categories. For example, in the HumanaChoice audit, acute stroke was unsupported in all 20 sampled enrollee-years, while acute myocardial infarction, breast cancer, colon cancer, and ovarian cancer were each unsupported in 19 of 20.

In the UnitedHealthcare of Wisconsin, Inc. audit, breast and colon cancer codes were unsupported in all 20 sampled enrollee-years reviewed for those categories. Additionally, acute stroke, acute myocardial infarction, and ovarian cancer codes were unsupported in 19 of 20, while prostate cancer codes were unsupported in 18 of 20.

The UnitedHealthcare Benefits of Texas, Inc. audit reported similarly high rates, with acute stroke and prostate cancer codes unsupported in 19 of 20 and lung, breast, colon, and ovarian cancer codes unsupported in 18 of 20.

The audits also revealed what the OIG characterized as potentially mis-keyed diagnosis. In these cases, medical records contained multiple diagnoses associated with a particular condition, but only one diagnosis, “associated with an unrelated condition,” was submitted. The OIG identified potentially mis-keyed diagnoses in:

• 18 of 30 sampled enrollee-years in the UnitedHealthcare Benefits of Texas, Inc. audit
• 22 of 50 sampled enrollee-years in the UnitedHealthcare of Wisconsin, Inc. audit
• 10 of 20 sampled enrollee-years in the HumanaChoice audit

The three reports identify several diagnosis codes among the potentially mis-keyed diagnoses, including C78.00 (secondary malignant neoplasm of unspecified lung), E78.00 (pure hypercholesterolemia, unspecified), G62.9 (polyneuropathy, unspecified), and I62.9 (nontraumatic intracranial hemorrhage, unspecified).

Editor’s note: To read the review of UnitedHealthcare Benefits of Texas, Inc., click here. To read the review of UnitedHealthcare of Wisconsin, Inc., click here. To read the review of HumanaChoice, click here. To read additional coverage from JustCoding, click here.