How Much Medicare Part D Waste? A Data-Driven Estimate

The U.S. government estimates that Medicare fraud, waste, and abuse costs taxpayers tens of billions annually. Using the complete 2023 CMS Part D prescribing dataset, we built a bottom-up estimate of waste that's visible in the data.

1. The Brand-Name Premium: $146.00B

Brand-name drugs consumed $185.46B of Medicare Part D spending in 2023, despite representing only 13.4% of total claims. Generic equivalents cost $39.45B for the remaining claims. The raw premium — the difference between what Medicare paid for brands and what it paid for generics — is $146.00B.

Not all of this is "waste" — some brand drugs have no generic alternative, and some patients legitimately need brand formulations. But studies consistently estimate that 20-30% of brand prescribing could safely switch to generics, representing billions in potential savings.

2. Excluded Providers Still Billing: $80.0M

We cross-referenced the CMS prescribing data against the OIG's List of Excluded Individuals and Entities (LEIE). The result: 82 providers on the federal exclusion list appear in active 2023 Medicare Part D prescribing data, generating $80.0M in drug costs.

Federal law prohibits excluded individuals from participating in federal healthcare programs. Every dollar billed by these providers is, by definition, improper.

3. High-Risk Provider Outliers: $167.9M

Our multi-component risk scoring model identified 233 high-risk providers whose prescribing patterns deviate significantly from their specialty peers. These providers generated $167.9M in total drug costs.

4. Opioid Overprescribing Excess

Among the 6,706 flagged providers in our high-risk dataset, 5,850 have opioid prescribing rates above 20%. These providers generated $1.16B in drug costs. While some specialties (pain management, oncology) legitimately prescribe opioids at high rates, the excess above specialty medians represents a quantifiable cost of the opioid pipeline.

5. Which Specialties Over-Prescribe Brands?

Brand preference varies dramatically by specialty. The top 10 brand-heavy specialties:

The Total: A Conservative Estimate

These categories overlap — an excluded provider may also be a high-cost outlier. But even conservatively, the data suggests tens of billions in addressable waste within Medicare Part D prescribing. The brand-generic gap alone exceeds $100 billion.

What Can Be Done?

Several policy levers could reduce waste:

• Mandatory generic substitution where bioequivalent generics exist
• Real-time LEIE checking before claims are processed
• Peer-adjusted spending alerts for providers who deviate significantly from specialty norms
• Opioid prescribing limits with specialty-specific thresholds
• IRA drug price negotiation — already targeting the most expensive drugs