Hospital patients waiting in an emergency room or convalescing after surgery are being confronted by an unexpected visitor: a debt collector at bedside.

This and other aggressive tactics by one of the nation’s largest collectors of medical debts, Accretive Health, were revealed on Tuesday by the Minnesota attorney general, raising concerns that such practices have become common at hospitals across the country.

The tactics, like embedding debt collectors as employees in emergency rooms and demanding that patients pay before receiving treatment, were outlined in hundreds of company documents released by the attorney general. And they cast a spotlight on the increasingly desperate strategies among hospitals to recoup payments as their unpaid debts mount.

To patients, the debt collectors may look indistinguishable from hospital employees, may demand they pay outstanding bills and may discourage them from seeking emergency care at all, even using scripts like those in collection boiler rooms, according to the documents and employees interviewed by The New York Times.