For patients admitted with the most severe diagnoses, Medicare's promise of coverage has a significant asterisk. Beneficiaries undergoing ECMO or tracheostomy with prolonged mechanical ventilation paid an average of $30,646 out of pocket per discharge in 2023, more than double the $15,085 they paid in 2013. That's a 103.2% increase in ten years, against a 37.6% rise in what Medicare itself paid for the same cases.

The gap between those two growth rates is the story.

When Cost-Sharing Outpaces the Program's Own Payments

DRG 003 (ECMO or tracheostomy with mechanical ventilation over 96 hours) sits at the extreme end of the acuity spectrum. Medicare's average payment for these cases reached $185,475 in 2023, which sounds like comprehensive coverage until you see the beneficiary's share: $30,646 per discharge. The program's payment grew by $50,695 over the decade. The beneficiary's share grew by $15,561. In percentage terms, the patient's burden grew nearly three times faster.

Kidney transplants tell an even starker story. For DRG 652, Medicare's average payment rose just 4.9% from 2013 to 2023, a $1,235 increase. Beneficiary out-of-pocket costs for the same DRG rose 73.8%, a $7,155 increase, reaching $16,853 per discharge. At that level, the beneficiary's cost-sharing represents a substantial fraction of the $26,563 total Medicare payment. For a patient recovering from a transplant, that's not a copay. It's a financial event.

Cardiac valve procedures show the same pattern. Beneficiary out-of-pocket costs for DRG 219 (cardiac valve without catheterization, with MCC) rose 137% from 2013 to 2023, reaching $11,145. The comparable DRG 220 (without MCC) rose 132.2% to $9,104. Both more than doubled in a decade. Medicare's payment for DRG 219 grew 16.5% over the same period.

The Geography of Cost-Sharing

The burden isn't distributed evenly across the country. For septicemia and severe sepsis without mechanical ventilation (DRG 871), one of the highest-volume diagnoses in Medicare, patients in metropolitan core hospitals paid an average of $2,655 out of pocket per discharge in 2023. That figure represented 14.9% of the total payment of $17,794.

In micropolitan core hospitals serving smaller urban clusters, the same patients paid $1,550 per discharge. In small town core hospitals, the out-of-pocket share fell to 8.8% of total payment. The metropolitan premium for sepsis care is $1,105 per admission, roughly 71% more than what a patient in a small town pays for the same diagnosis.

For context on how far cost-sharing can reach into lower-acuity cases: in metropolitan hospitals, beneficiary out-of-pocket costs for esophagitis, gastroenteritis, and miscellaneous digestive disorders (DRG 392) represented 26.5% of total payment per discharge. More than a quarter of the bill, for a digestive disorder.

One DRG Where Medicare Paid Less and Patients Still Paid More

Combined anterior and posterior spinal fusion with CC (DRG 454) is the only DRG in the top 20 where Medicare's average payment actually fell from 2013 to 2023, dropping $4,584 (8.3%). Beneficiary out-of-pocket costs for the same procedure rose 16.8% to $9,011.

That combination, a declining program payment alongside a rising patient share, is a clean illustration of how cost-sharing and program reimbursement can move in opposite directions. The total resources flowing to the hospital may have changed, but the patient's portion of the bill went up regardless.

Coronary bypass with cardiac catheterization without MCC (DRG 234) reached $8,144 per discharge in 2023, an 84.4% increase from 2013. These are not marginal procedures. They are among the most common high-acuity interventions in Medicare, performed on hundreds of thousands of beneficiaries annually.

The structural question the data raises is about kidney transplants specifically: beneficiary out-of-pocket costs for DRG 652 rose 73.8% over ten years while Medicare's payment for the same cases rose 4.9%. What contracting or policy mechanisms are driving that divergence, and which specific hospitals account for the highest individual out-of-pocket burdens among transplant recipients?