Rehab hospitals that help people recover from major surgeries and injuries have become a highly lucrative slice of the health care business. But federal data and inspection reports show that some run by the dominant company, Encompass Health Corporation, and other for-profit corporations have had rare but serious incidents of patient harm and perform below average on two key safety measures tracked by Medicare.

Yet even when inspections reveal grave cases of injury, federal health officials do not inform consumers or impose fines the way they do for nursing homes. And Medicare doesn’t provide easy to understand five-star ratings as it does for general hospitals.

In the most serious problems documented by regulators, rehab hospital errors involved patient deaths.

In Encompass Health’s hospital in Huntington, W.Va., Elizabeth VanBibber, 73, was fatally poisoned by a carbon monoxide leak during construction at the facility.

At its hospital in Jackson, Tenn., a patient, 68, was found dead overnight, lying on the floor in a “pool of blood” after an alarm that was supposed to alert nurses that he had gotten out of bed had been turned off.

In its hospital in Sioux Falls, S.D., a nurse gave Frederick Roufs, 73, the wrong drug, one of 26 medication errors the hospital made over six months. He died two days later at another hospital.