Medicare Advantage Is Under the Microscope. Here’s What’s Actually Happening.

If you follow healthcare enforcement, you’ve probably seen the headlines about Medicare Advantage investigations. But the actual situation is more nuanced than most coverage suggests.

Here’s what we know.

The scale of MA is enormous. Over 54% of Medicare beneficiaries, roughly 33 million people are now enrolled in Medicare Advantage plans. That’s up from 19% in 2007. The Congressional Budget Office projects it will hit 64% by 2034.

The scrutiny is intensifying. The DOJ has active litigation against several major insurers, including UnitedHealth, Elevance Health, and Kaiser Permanente, over allegations of improper diagnosis coding. In July 2025, UnitedHealth confirmed it’s cooperating with both criminal and civil investigations into its Medicare billing practices.

The core allegation is “upcoding.” The government’s concern is that some plans may be documenting diagnoses more aggressively than medical records support capturing conditions that boost risk adjustment payments without corresponding clinical evidence.

But proof is complicated. A recent case illustrates the challenge. After more than a decade of litigation, a special master recommended dismissing the DOJ’s case against UnitedHealth, finding the government hadn’t proven its claims. The case alleged $2.1 billion in overpayments, but the special master concluded the evidence relied too heavily on “speculation and assumptions.”

The gap between clinical documentation and coding requirements is often unintentional. Providers document based on clinical judgment. But the standards CMS uses for risk adjustment are more stringent than typical clinical practice. A provider might reasonably believe a patient has a condition without documenting it in the specific way regulators require.

This creates exposure.

The organizations best positioned to defend themselves are those that audit proactively, maintain clear documentation standards, and can demonstrate their chart review programs are calibrated to accuracy, not revenue optimization.