The price Medicare pays for joint replacement had hardy changed in two decades when the Centers for Medicare and Medicaid Services (CMS) began an experimental program to pay bundled payments for a full 90-day episode of care. The program was designed to save Medicare money while rewarding surgeons who keep costs down and penalizing those whose costs are higher.
Surgeons whose patients cost Medicare less than the lump sum over 90 days get a portion of their savings as a reward. Surgeons who don’t save Medicare money face penalties large enough to bankrupt them.