Every year, US health insurance companies deny tens of millions of patient claims for medical expense reimbursements, and the tide of those denials has been rising.
The Washington Post on Monday cited surveys of doctors and other healthcare providers.
Insurers also have been increasingly demanding that doctors obtain approval before providing treatment, similar surveys show, causing delays in patient care that the American Medical Association says are "devastating," news agency reported.
While several states have passed legislation trying to restrict such practices amid growing public anger, insurers defend the coverage denials and "pre-authorisation" requirements. They say those measures are meant to contain rising costs and that their methods comply with federal and state regulations.
"Most frustrating, according to patient advocates, is that insurance companies often act without explanation, sending denial letters that offer only sparse justifications," said the report.