Seniors across the country are wearing very expensive bandages.

Made of dried bits of placenta, the paper-thin patches cover stubborn wounds and can cost thousands of dollars per square inch.

Some research has found that such “skin substitutes” help certain wounds heal. But in the past few years, dozens of unstudied and costly products have flooded the market.

Bandage companies set ever-rising prices for new brands of the products, taking advantage of a loophole in Medicare rules, The New York Times found. Some doctors then buy the coverings at large discounts but charge Medicare the full sticker price, pocketing the difference.

Partly because of these financial incentives, many patients receive the bandages who do not need them. The result, experts said, is one of the largest examples of Medicare waste in history.

Private insurers rarely pay for skin substitutes, arguing that they are unproven and unnecessary. But Medicare, the government insurance program for seniors, routinely covers them. Spending on skin substitutes exceeded $10 billion in 2024, more than double the figure in 2023, according to an analysis of Medicare data done for The Times by Early Read, a firm that evaluates costs for large health companies.

Medicare now spends more on the bandages than on ambulance rides, anesthesia or CT scans, the analysis found.