MINNEAPOLIS — An estimated 320,000 seniors across Minnesota will need to change Medicare health plans in the coming months.

Residents with Medicare Cost health plans have to switch because of a federal law eliminating the policy next year in most of the state, The Star Tribune reported .

The 2003 law says Medicare Cost plans cannot be offered in areas with significant competition from Medicare Advantage plans. Congress delayed the law’s implementation until 2019.

Medicare Cost plans will be eliminated in almost 70 Minnesota counties, including Hennepin and Ramsey counties. The plans will still be available in about 20 counties, such as St. Louis County.

About 20 million people in the U.S. are covered by Advantage programs, while only about 630,000 people had Cost plans in June.

“The government is not trying to take away benefits,” said Sean Creighton, a vice president in the policy practice with Avalere, a health care consultancy in Washington, D.C. “What they are trying to do is simplify the administrative structure and have health plans take financial responsibility for managing the health care utilization of enrollees.”

Insurers, government agencies and consumer advocates have begun informing residents about the transition but details of the 2019 coverage options won’t be available until next month.

Some enrollees will be automatically enrolled in a comparable Advantage plan unless they choose otherwise, according to insurance companies. Up to 125,000 Minnesota residents may be directed to a new plan this way.

State officials urge residents to find plans that are affordable and provide the right amount of access.

“They need to make sure their provider is going to be in the network,” said Kelli Jo Greiner, health policy analyst with the Minnesota Board on Aging. “The Medicare Advantage plans usually have smaller provider networks than the Medicare Cost plans did.”