(Bloomberg) — An Obamacare experiment to lower health care costs may expand after recording more than $384 million in savings in its first two years, Health & Human Services Secretary Sylvia Mathews Burwell said Monday.

The department is now considering how to broaden the program to other parts of Medicare. The efforts saved about $300 per Medicare beneficiary per year, Burwell said. Known as Pioneer Accountable Care Organizations, the program seeks to reduce spending by better managing care for Medicare patients with chronic diseases such as diabetes.

"An innovative payment model created as a pilot project by the Affordable Care Act generated substantial savings to Medicare," Burwell said in a speech at the American Hospital Association conference in Washington. "The model has delivered high-quality patient care without limiting coverage or benefits."