A government report released Thursday found health insurance companies had combed through patient charts to obtain billions of dollars of additional payments from the federal Medicare program.

The report, from the federal inspector general’s office, examined payments billed by insurers for those covered by private Medicare Advantage plans, which are increasingly popular and heavily promoted by the Trump administration. The findings showed that insurers were adding on conditions like diabetes and even cancer, reporting that patients were sicker, to receive higher payments from Medicare.

While the inspector general’s office did not conclude that insurers were overbilling the program, it raised concerns about whether the payments were justified and whether patients were getting appropriate care.

About 21 million people enrolled in these private plans in 2018, accounting for well over a third of those covered under the federal insurance program for those who are over 65 or have disabilities. Of the $711 billion spent last year on the Medicare program, $210 billion went to Medicare Advantage. Not only has the administration increased allocations for the private plans, it also has permitted them to offer more benefits — like telemedicine visits and transportation for medical appointments — to attract customers.