Aetna: One-Way Reviews and the BMI Records Behind the Codes

In the Aetna Medicare Advantage risk adjustment settlement, the insurer agreed to pay $117.7 million to resolve allegations of one-way chart reviews and unsupported morbid-obesity coding. The government alleged that Aetna used medical-record reviews to claim more money while ignoring findings that called for money back. A separate allegation concerned morbid-obesity codes that conflicted with recorded body mass index information. A former Aetna risk-adjustment coding auditor brought the whistleblower case behind that part of the settlement.

How the Diagnosis Became Aetna’s Revenue

Aetna’s Medicare Advantage plans received monthly payments that rose with the expected healthcare costs of their members. The Centers for Medicare & Medicaid Services used diagnosis codes submitted by the insurer to make those adjustments.

Medicare buys insurance coverage from the plan at a monthly per-person price. Eligible diagnoses feed into condition categories, which contribute to a member’s risk score. As HHS-OIG explains the calculation, that score multiplies the plan’s base payment rate.

The coding work can happen after the care. A retrospective chart review goes back through a provider’s existing records to identify diagnoses the provider did not report. In Aetna’s case, the government said the insurer obtained the records, retained coders to read them and used their findings to submit additional diagnoses. The same review could also expose a previously submitted diagnosis that the chart did not support.

The financial incentive extends across the industry. A 2024 presentation of findings from an Urban Institute workgroup, Reimagining the Medicare Advantage Risk Adjustment Program, reports expert concern about the effort devoted to capturing diagnoses at the highest severity: panelists described the push to code every possible diagnosis at its most severe level as effort that does nothing for Medicare or the people it covers.

Aetna’s alleged choice about which review findings to use shows how that incentive can reach the correction process itself.

The One-Way Chart Reviews for Payment Year 2015

Aetna’s one-way chart reviews allegedly acted on findings that increased payments while leaving unsupported diagnoses in place. The district announcement assigns $106.2 million of the settlement to this conduct for payment year 2015.

According to the government, Aetna’s coders identified additional conditions supported by the charts, and the insurer submitted those codes to CMS for more money. But their reviews did not substantiate some diagnoses that providers had reported and Aetna had already submitted. Withdrawing those codes would have required Aetna to reimburse Medicare. Under the alleged practice, taxpayers funded the overpayments while Medicare went unreimbursed.

The government alleged that Aetna used the favorable results and ignored the unfavorable ones. The charts had been obtained. The coding work had been done. The alleged failure came when Aetna decided which findings would change what Medicare paid.

For someone inside a review operation, that distinction matters. A system can produce useful review findings while the payment submissions reflect only the additions. The review’s output and the insurer’s response tell different parts of the story. We examine both, including what happened to diagnoses the review failed to support.

The government’s complaint against Anthem describes the same financial pressure in an executive’s reported response to changing its chart-review program: in March 2016, the head of Anthem’s Medicare R&R group told two peers she wanted chart review left exactly as it was, calling it a high-return moneymaker for Anthem.

In that separate case, the government also alleged that Anthem had no process to compare previously submitted codes with its vendor’s findings for the same patients and visits, although its programmers could perform the comparison. That allegation puts a concrete business decision behind the missing corrections: whether to look for errors that would reduce the return from chart review.

Morbid-Obesity Codes Against the BMI Record

Aetna’s morbid-obesity settlement concerned payment years 2018 through 2023 and diagnoses that the government said conflicted with patients’ recorded BMI. The district announcement assigns $11.5 million to allegations that Aetna knowingly submitted or failed to delete those inaccurate codes to obtain higher payments.

The national announcement explains that medical records for people diagnosed as morbidly obese typically include body mass index recordings. The alleged contradiction was inside the information available for review: the record carried a diagnosis that raised payment alongside BMI information inconsistent with that diagnosis.

For a coding auditor, that is a different problem from finding a diagnosis the provider omitted. The question is what happened when information in the chart undermined the code. According to the government’s account, Aetna submitted or retained the inaccurate morbid-obesity diagnoses, and CMS paid more because of them.

The government also alleged that Aetna certified its diagnosis data as accurate and truthful while submitting inaccurate information and failing to withdraw it and repay CMS.

A similar allegation appeared in Cigna’s separate settlement: the government alleged that Cigna submitted or retained morbid-obesity codes despite BMI information inconsistent with them. The recurring issue is the handling of contradictory documentation. A diagnosis that increases payment and the information questioning it can sit in the same record.

Two Agreements and the Auditor’s Reward

The national Aetna announcement lists separate chart-review and morbid-obesity agreements. It ties the former auditor’s qui tam case and reward specifically to the morbid-obesity settlement.

That settlement provided for the auditor to receive approximately $2 million.

The auditor’s role is the practical point for readers doing this work: reviewing diagnosis coding can put an employee close to the contradiction between the medical documentation and the data used for payment.

A whistleblower case under the False Claims Act can pay 15% to 30% of what the government recovers.

Aetna Refused Compliance Oversight

Aetna refused to enter a corporate integrity agreement with HHS-OIG as part of the resolution. The Inspector General’s Aetna entry dates that refusal to March 9, 2026 and lists ten years of heightened scrutiny.

HHS-OIG says it reserved the right to exclude Aetna from federal health care programs for the alleged conduct and may use tools to monitor the company’s compliance. Aetna agreed to pay for the alleged coding failures, but refused the compliance oversight the Inspector General sought.

What the Review Found and What Happened Next

The Aetna allegations turn on the gap between what medical records showed and what the insurer submitted or left in place. For chart-review staff, the useful comparison is between the review findings and the additions and deletions that followed. For a coding auditor, it is between the diagnosis, the contradictory documentation and the decision to retain or correct the code.

Those are connections we work through with an insider. A review result can show that the documentation problem was visible. Submission and correction records can show what happened afterward. Instructions and responses to audit findings can explain why. The concern about known overpayments left in place reaches the decisions made after somebody has already looked at the chart.

The government’s Aetna account describes an insurer paying to review records, using the results to increase payments and allegedly ignoring the results that called for repayment. The person who understands that workflow can explain the decisions behind the codes Medicare received.

You Know What the Coding Review Found

If you saw unsupported codes survive a review or contradictory BMI records set aside, talk with our whistleblower experts about the decisions behind those submissions. We work with you to build your strongest Medicare Advantage whistleblower case around what your coding knowledge reveals, bring in Medicare Advantage fraud whistleblower lawyers who know risk adjustment cases, and stay beside you through the pursuit of a recovery.