WASHINGTON (AP) — President Joe Biden on Thursday ordered government health insurance markets to reopen for a special sign-up window, offering uninsured Americans a haven as the spread of COVID-19 remains dangerously high and vaccines aren't yet widely available.

Biden signed an executive order directing the HealthCare.gov insurance markets to take new applications for subsidized benefits, something Donald Trump's administration had refused to do. He also instructed his administration to consider reversing other Trump health care policies, including curbs on abortion counseling and the imposition of work requirements for low-income people getting Medicaid.

“There’s nothing new that we’re doing here other than restoring the Affordable Care Act and restoring Medicaid to the way it was before Trump became president,” Biden said as he signed the directives in the Oval Office. He declared he was reversing “my predecessor’s attack on women’s health."

The actions were only the first steps by Biden, who has promised to build out former President Barack Obama’s health care law to achieve a goal of coverage for all. While Biden rejects the idea of a government-run system that Sen. Bernie Sanders has pushed for in his “Medicare for All” proposal, his more centrist approach will require congressional buy-in. But opposition to “Obamacare” runs deep among Republicans.

The most concrete short-term impact of Biden's orders will come from reopening HealthCare.gov insurance markets as coverage has shrunk in the economic turmoil of the coronavirus pandemic. That's an executive action and no legislation is required.

The new “special enrollment period” will begin Feb. 15 and run through May 15, the White House said. It will be coupled with a promotional campaign and a call for states that run their own insurance markets to match the federal sign-up opportunity.

The Biden administration has ample resources for marketing, said Karen Pollitz, a health insurance expert with the nonpartisan Kaiser Family Foundation. The foundation estimates that the Trump administration left unspent about $1.2 billion in user fees collected from insurers to help pay for running the marketplaces.

“The reason it wasn’t spent is the Trump administration spent its time in office cutting services that support consumer enrollment,” Pollitz said. “All the while the user fee revenue was coming in, (but) they were not allowed to spend it on anything other than marketplace operations.”

Created under the Obama-era Affordable Care Act, the marketplaces offer taxpayer-subsidized coverage regardless of a person’s medical history or preexisting conditions, including COVID-19.

Biden also ordered the immediate reversal of a federal policy that bars taxpayer funding for international health care nonprofits that promote or provide abortions. Known as the Mexico City Policy, it can be switched on or off depending on whether Democrats or Republicans control the White House. Abortion rights supporters call it the “global gag rule.”

The new president's signing of a growing stack of executive orders is bringing increasing criticism from Republicans and also from some of his allies, especially after Democrats lambasted Trump when he acted on his own. Biden's team says he's looking to Congress for major legislation but feels that certain actions are crucial in the meantime.

Some directives he issued Thursday could take months to carry out.

He instructed the Department of Health and Human Services to consider rescinding Trump regulations that bar federally funded family planning clinics from referring women for abortions.

HHS will also reexamine a Trump administration policy that allows states to impose work requirements as a condition for low-income people to get Medicaid health insurance. Work requirements have been blocked by federal courts, which found that they led to thousands of people losing coverage and violated Medicaid's legal charge to provide medical services. The Supreme Court has agreed to hear the issue.

And Biden directed HHS to review Trump policies that could undermine protections for people with health problems, such as a rule that facilitated the sale of short-term health insurance plans that don't have to cover preexisting medical conditions.

Such changes cannot happen overnight. Rescinding a federal regulation requires a new regulation, which has to follow an established legal process that involves considering different sides of an issue.

Former Trump health policy adviser Brian Blase said the Biden administration has to take care it doesn't throw out some policies intended to help solidly middle-class people who don't qualify for financial assistance under Obama's law.

“Obamacare plans are generally only attractive to people who receive large subsidies to buy them,” said Blase. He cited a Trump policy that allows employers to provide tax-free money for workers to buy individual plans.

The abortion-related actions brought Biden immediate praise from women's rights groups, as well as condemnation from social and religious conservatives. Under President Trump, abortion opponents had free rein to try to rewrite federal policy, but now the political pendulum has swung back. Trump's abortion counseling restrictions led Planned Parenthood affiliates to leave the federal family planning program.

Biden campaigned on repealing longstanding federal prohibitions against taxpayer funding for most abortions, but that was not part of Thursday's orders. A change of that magnitude to a group of laws known as the Hyde Amendment would require congressional approval.

Biden's nominee for health secretary, California Attorney General Xavier Becerra, has not yet been confirmed by the Senate, but the White House said that will not stop health agencies from immediately going to work on the president's directives.

The idea of reopening Obamacare's health insurance markets in the pandemic has had broad support from consumer, medical, and business organizations. The main insurer trade group, America's Health Insurance Plans, applauded Biden's move.

As the number of uninsured Americans grew because of job losses in the pandemic, the Trump administration resisted calls to reopen HealthCare.gov. Failure to repeal and replace Obamacare was one of the former president's most bitter disappointments. His administration continued trying to find ways to limit the program or unravel it entirely. A Supreme Court decision on Trump’s final legal challenge to the Affordable Care Act is expected this year.

Experts agree that number of uninsured people has risen because of layoffs in the coronavirus economy, but authoritative estimates await government studies due later this year. While some estimates cite 5 million to 10 million newly uninsured people, the nonpartisan Congressional Budget Office says its analysis suggests a smaller number.

Nonetheless, the CBO projects that nearly 32 million Americans are uninsured and of those, about 2 in 3 are eligible for some kind of subsidized coverage.

The Obama-era health care law covers more than 23 million people through a mix of subsidized private insurance sold in all states, and expanded Medicaid adopted by 38 states.