HHS report: 'ObamaCare' keeping Medicare costs low

Both the Medicare actuaries and the Congressional Budget Office have also projected that low cost increases will continue for several years — largely because of the healthcare law's cuts in payments to insurance companies and healthcare providers.

Republicans say those cuts will eventually lead doctors to stop participating in Medicare, which will mean fewer services for seniors. But the HHS report notes that the health law has not directly cut any Medicare benefits, and has added several new benefits, including preventive screenings.

"The Affordable Care Act is an important factor contributing to slow growth in spending per beneficiary in 2011 and 2012, and is the primary cause of the projections of continued slow growth over the next decade," the HHS report states.