Medicare recipients could see a sizable new out-of-pocket charge for home health visits if Congress follows through on a recommendation issued Thursday by its own advisory panel. Until now, home health visits from nurses and other providers have been free of charge to patients. But the Medicare Payment Advisory Commission says a copayment is needed to discourage overuse of a service whose cost to taxpayers is nearing $20 billion a year amid concerns that fraudsters are also taking advantage. The panel did not prescribe an amount, but its staff has suggested the charge be $150 for a series of related visits. Medicare requires copays for many other services, so home health has been the exception, not the rule.