(Reuters) - U.S. health insurer Anthem Inc is pulling back from 16 of 19 pricing regions in California where it offered Obamacare options this year, state officials said on Tuesday.

The office building of health insurer Anthem is seen in Los Angeles, California February 5, 2015. REUTERS/Gus Ruelas

The move, which takes effect for 2018, means Anthem will offer Obamacare coverage in three pricing regions comprising 28 counties in California.

That is just 41 percent of its current enrollment, or about 108,000 consumers, leaving some 153,000 consumers without Anthem Obamacare options, state officials said.

Anthem blamed the move in part on uncertainty over whether the Trump administration would maintain subsidies that keep costs down among the factors that have “led to an increasing overall lack of predictability.” As a result, the insurer said it does not allow them to provide affordable plan choices for all California consumers.

“The market for these plans has become unstable. And with federal rules and guidance changing, it’s no longer possible for us to offer some of those plans,” Brian Ternan, president of Anthem Blue Cross of California, said in a statement on the company’s website.

U.S. President Donald Trump on Monday threatened to cut off subsidy payments that make the plans affordable for lower income Americans and help insurers to keep premiums down, after efforts to repeal the law signed by his predecessor, President Barack Obama, failed in Congress.

Trump has repeatedly urged Republican lawmakers to keep working to undo Obama’s Affordable Care Act which has extended insurance to some 20 million more Americans.

Anthem said it would offer individual plans both in and out of the state’s exchanges in the three regions made up of those 28 counties.

Anthem, which announced last month that it was mostly exiting individual plans in Wisconsin and Indiana, said the decision does not affect those with employer-provided insurance, Medicare Advantage, Medicare Supplement, Medi-Cal or “grandfathered” plans purchased before March 2010.

Also on Tuesday, federal regulators extended the deadline for insurers in Michigan to submit 2018 Obamacare individual plan premium rates as they await more clarity from the Trump administration, Michigan’s Department of Insurance and Financial Services said.

Michigan said it was given permission by the Centers for Medicare and Medicaid Services (CMS) to postpone the release of its proposed 2018 rate changes for 30 days. The state now plans to release them on September 1.