UnitedHealth Group Under DOJ Investigation for Medicare Advantage Risk Coding Practices

UnitedHealth Group (UHG) is currently under criminal investigation by the U.S. Department of Justice (DOJ) over allegations of Medicare fraud tied to its Medicare Advantage (MA) billing practices. The investigation focuses on whether UHG used questionable methods to inflate patient risk scores and thereby increase the payments it received from the Centers for Medicare & Medicaid Services (CMS).

Understanding the Core of the Allegation: Risk Score Inflation

At the center of the DOJ investigation are claims that UHG improperly leveraged chart reviews and in-home Health Risk Assessments (HRAs) to identify additional diagnoses not confirmed through active treatment. These diagnoses were then used to boost patient risk scores, which directly influence the amount CMS reimburses MA plans.

This is not a new tactic in the Medicare Advantage space. CMS has long permitted the use of HRAs and retrospective chart reviews for risk adjustment. However, diagnoses must be tied to a face-to-face clinical encounter, be properly documented in the medical record, and coded in accordance with ICD-10-CM standards. When these conditions are not met, submitting the data can cross into fraudulent territory.

From Diagnosis Codes to Reimbursement: ICD-10-CM and HCC Explained

Risk scores are calculated by mapping ICD-10-CM diagnosis codes to Hierarchical Condition Categories (HCCs), each of which carries a risk weight. The higher the total HCC score, the higher the CMS payment to the insurer.

Examples include:

• E11.9 (Type 2 Diabetes without complications) maps to HCC 19

• I50.32 (Chronic diastolic heart failure) maps to HCC 85

• C34.91 (Lung cancer) maps to HCC 8

If a health plan discovers these diagnoses — through a chart review or HRA — and adds them to a patient’s profile, their risk score increases. The problem arises when these diagnoses were never clinically validated or followed up with care.

The Whistleblower's Allegations

This DOJ probe was largely triggered by a whistleblower lawsuit filed by a former UnitedHealth employee. The suit alleges that UHG:

• Used algorithms to identify diagnoses not previously coded.

• Had nurses validate these diagnoses through chart snippets without clinical context.

• Failed to ensure those diagnoses were confirmed in actual medical care.

• Submitted the codes to CMS anyway, boosting their revenue.

The whistleblower estimates that UHG may have improperly received nearly $2 billion in Medicare payments through these unsupported diagnoses. Though a court-appointed special master recommended dismissing the case for lack of evidence, the DOJ strongly objected — signaling its commitment to pursue criminal liability if wrongdoing is confirmed.

Your Employees Are Your Risk — And Your Defense

Having worked in this space, I’ve seen firsthand how risk adjustment programs are managed. In fact, I once interviewed for a Risk Management role at a large insurer. My background in clinical work, auditing, coding, and technical operations made me a candidate for a position developing methods to parse large volumes of patient records. The goal was to uncover diagnoses that may have been “missed” by providers, which could be added to increase Medicare Advantage reimbursement.

At the time, I was struck by how routine it all sounded. It wasn’t called fraud — it was called optimization. The systems were automated, reviewed internally, and framed as compliant with CMS guidance. But I kept asking: who ensures these diagnoses are real and relevant? How do we protect against bias in retrospective reviews?

I didn’t take the role. But I left with a strong impression: ethical boundaries in these programs are often managed from the inside out. If you don’t have strong compliance, clear documentation standards, and empowered staff — your first and most significant threat will always come from within.

Whistleblowers are not fringe players. They are often skilled professionals, frustrated by lack of oversight or resistance to internal reporting. And when they feel ignored, they take their concerns straight to federal agencies.

Market Fallout and Corporate Chaos

UnitedHealth’s reputation and stock price have taken major hits. On May 15, 2025, shares fell by 17 percent — part of a staggering 50 percent decline over one month. This came shortly after the sudden resignation of CEO Andrew Witty and the return of former CEO Stephen Hemsley to stabilize operations (Wall Street Journal).

The company was already reeling from a massive cyberattack that delayed provider payments nationwide, and from the tragic death of Brian Thompson, a senior executive with UnitedHealthcare.

Medicare Advantage Under Scrutiny

This isn’t just about UHG. The DOJ has begun to pivot its focus from providers to the plans themselves. Private insurers now manage care for more than half of all Medicare beneficiaries, and a growing number of government reports have raised concerns about overbilling, inflated risk scores, and a lack of oversight in MA payment models.

The broader implication: what may have once been standard industry practice could soon be redefined as criminal if compliance and documentation fail to meet the letter of CMS policy.

How Precisian Group Can Help

Precisian Group exists to help organizations navigate these risks and do it right. We specialize in strengthening internal controls, evaluating automated coding systems, and training staff to align with CMS’s evolving expectations.

• Healthcare Consulting: Strategic guidance for compliance, policy, and payer relations

• Data Analytics: Tools that track HCC trends, billing anomalies, and audit risk

• AI & Automation Audits: Review of algorithms used in chart reviews and HRA coding to ensure defensibility

• Training & Internal Reporting: Build the culture, channels, and clarity needed to prevent internal escalation

If you’re using HRAs, retrospective reviews, or any risk adjustment model, we can help you safeguard it from regulators and from the possibility of your own systems going too far.

Contact Precisian Group today to ensure your risk adjustment strategy protects your patients, your people, and your future.