Private insurance companies that participate in Medicare under the Medicare Advantage program and its predecessors have cost the publicly funded program for the elderly and disabled an extra $282.6 billion since 1985, most of it over the past eight years. In 2012 alone, private insurers were overpaid $34.1 billion.

That's wasted money that should have been spent on improving patient care, shoring up Medicare's trust fund or reducing the federal deficit, the researchers say.

Medicare’s costs will jump by $7.43 billion next year – the equivalent of $149 for each of the nearly 50 million beneficiaries in the program – due to an unprecedented intervention last week by the Obama administration in the way privately run, for-profit Medicare Advantage (MA) plans, which are also known as Medicare HMOs, are paid by the government.

That's according to a report from Physicians for a National Health Program (PNHP).