WASHINGTON (AP) — Elizabeth Warren announced Friday that she won’t immediately push to give every American government-funded health care and instead will work to oversee passage of a sweeping “Medicare for All” program by the end of her third year if elected president — a significant step away from a plan she’s long championed.

The Massachusetts Democratic senator released a health care transition plan that vows to build on existing programs, including the Obama administration’s signature Affordable Care Act, to expand public health insurance during her first 100 days in office. That’s different than sticking fully with a “public option” over a government-run system, which is backed by Warren’s more moderate presidential candidate rivals, including former Vice President Joe Biden.

Warren then says she’ll work with Congress to pass pieces of a universal coverage proposal more gradually, with the whole thing being ready “no later than” her third year in office.

Allowing more time underscores Warren’s — or any candidate’s — difficulty in delivering on government-funded universal health coverage. Winning congressional approval would be a heavy lift, no matter which party holds majorities in the House and Senate.

“Every serious proposal for Medicare for All contemplates a significant transition period,” Warren wrote in an online post. “My plan will be completed in my first term. It includes dramatic actions to lower drug prices, a Medicare for All option available to everyone that is more generous than any plan proposed by any other presidential candidate, critical health system reforms to save money and save lives, and a full transition to Medicare for All.”

Even as she continued to praise Medicare for All, though, Friday’s announcement represented a major move toward the political middle on an issue that has been one of the most important to voters in the Democratic primary — which begins Feb. 3 in Iowa.

Warren had previously said she would offer more details on how to implement her health care policy, but she revealed for the first time that it will take years. She also said that, rather than helping to shepherd Medicare for All through a divided Congress as a first priority, she’d start with passing “anti-corruption” measures meant to curb the influence of lobbyists, insurance and pharmaceutical companies.

This comes two weeks after Warren unveiled a much-scrutinized plan to pay for Medicare for All, which proposed raising most of the additional $20.5 trillion her campaign believes would be needed from taxes on businesses, wealthy people and investors — and not the middle class. But some experts sharply criticized that proposal for far underestimating how much universal health care would really cost.

Biden and Mayor Pete Buttigieg of South Bend, Indiana, have also for months said Warren’s plan is too much for the general election and may spook moderates and swing voters who aren’t ready to fully scrap private insurance. Both have instead called for expanding existing programs to cover more people who currently don’t have health insurance, a position Warren now says she’ll embrace in the short term.

Taking years to fully move the country to Medicare for All would give Warren time to convince people happy with their current, private insurance to accept a fully government funded system. But Friday’s announcement seems sure to raise more tough questions about health care for a candidate who has been struggling with it lately — following her riding improved polling throughout the summer to become one of the front runners in the crowded Democratic primary field.

Warren previously offered details on financing Medicare for All only after ducking questions about whether middle class tax increases would be needed to pay for weeks — including during the last two debates. Now, word that fully implementing that plan will move slowly could unsettle progressive Democrats.

The stakes high since Vermont Sen. Bernie Sanders, wrote the original Medicare for All bill and has made it his signature issue. Still, Warren is essentially acknowledging the high degree of political difficulty that would be involved in getting Medicare for All through Congress — and the relatively low chances of success given that interest groups including employers, hospitals, drug companies and insurers will be arrayed against it.

“Warren is trying to thread a very tricky political needle here,” said Larry Levitt of the nonpartisan Kaiser Family Foundation. “Warren clearly still supports Medicare for all, but she is not putting all of her eggs in that basket.”

She is also recognizing that incremental measures that progressives sometimes dismiss as not going far enough could have a real impact on people’s lives. That view was reinforced by a recent study by the Urban Institute and Commonwealth Fund policy centers, which concluded that Democrats have more than one way to get to coverage for all. It found that an approach similar to Biden’s would deliver about the same level of coverage as Sanders’ plan.

“Warren’s proposals to shore up the Affordable Care Act, lower drug prices, and create a public option would still provide substantial health care cost relief for people,” Levitt said.

__

Eds: Associated Press Writer Ricardo Alonso-Zaldivar contributed to this report.