BOSTON (AP) — Five networks of doctors and hospitals in eastern and central Massachusetts have joined a Medicare national experiment to improve care for seniors, and hopefully save taxpayers money as well.

Officials announced Monday that the Massachusetts networks are among 32 groups around the country that are becoming Pioneer Accountable Care Organizations, or ACOs.

The networks will take a coordinated approach to medicine so that risks like high blood pressure and elevated blood sugars are managed better and patients get help leading a healthier lifestyle.

The networks will be eligible for financial rewards if they improve care and lower costs.

About 860,000 of Medicare’s 47 million beneficiaries will be involved in the test. They’ll still be free to go to any doctor.

Officials hope the test will lead to a new model for all of Medicare.