Oregon Gov. Kate Brown has signed a landmark bill to provide free abortions for all, including illegal immigrants, by requiring insurance companies to cover the procedures and putting taxpayers on the hook for the tab.

Tuesday’s long-awaited signing of House Bill 3391, approved by the State Legislature July 5 with no Republican votes, triggered a torrent of criticism from conservatives along with praise from the pro-choice movement.

“Thank Kate Brown for signing the nation’s most progressive reproductive health bill into law today!” NARAL Pro-Choice Oregon said in a statement.

The $10.2 million Reproductive Health Equity Act includes $500,000 for abortions for the estimated 22,873 women who would be eligible for the Oregon Health Plan, the state’s Medicaid program, “except for their immigration status.”

Under the first-of-its-kind law, most of which goes into effect immediately, Oregon insurers must provide 100 percent coverage for abortions without co-pays or deductibles.

Those covered by Providence Health Care, a nonprofit Catholic health care provider, and the only Oregon insurance company that does not cover abortions, will have expenses reimbursed by the state.

“There are many things that make Oregon a wonderful state. Unfortunately, HB 3391 is not one of them,” said Gayle Atteberry, executive director of Oregon Right to Life. “Today, Gov. Brown demonstrated her extreme bias in favor of the abortion rights lobby, disregarding thousands of future Oregonians whose lives have been further endangered by making their elimination 100 percent expense-free.”

Jonathan Lockwood, spokesman for the Oregon Senate Republicans, predicted other blue states would follow Oregon’s lead.

“Everyone in America needs to see that Oregon’s former late-term abortion-lobbyist governor Kate Brown just forced Oregonians to fund against their will late-term and sex-selective abortions,” Mr. Lockwood said in an email. “Watch out; this is coming to a state near you.”

The measure represents a badly needed lifeline for Planned Parenthood, whose national client visits have declined in the past few years from 3 million to 2.4 million, according to the organization’s annual reports.

Even in Oregon, known for its robust pro-choice laws, four Planned Parenthood facilities have shut down in the recent years as the number of abortions has decreased by 15 percent from 2011 to 2014, according to the Guttmacher Institute.

The Pro-Choice Coalition of Oregon, which includes Planned Parenthood, said it helped draw up the law making Oregon “the first state to establish comprehensive, state-funded reproductive health coverage for women categorically excluded from Medicaid based on citizenship status” and “the first to codify no-cost abortion coverage in state statute.”

“We are so grateful for the bold leadership of Gov. Brown and legislative champions who understand that Oregonians don’t want reproductive health care attacked,” said Laurel Swerdlow, advocacy director of Planned Parenthood Advocates of Oregon. “Women, transgender and gender-nonconforming individuals, people of color, immigrants and people of faith are not going to silently stand around while politicians in Washington, D.C., try to take away our health care.”

Critics warned that the Oregon law would imperil the state’s federal funding because it violates the Weldon Amendment, the 2005 congressional provision that prohibits Health and Human Services funds for states that discriminate against health care providers that refuse to cover abortion.

“The saddest day of my life was when I had to vote on this bill, though of course I voted NO, there was no reason to actually run this bill at all,” state Rep. Bill Post, a Republican, said on Facebook. “Oregon should be ashamed and embarrassed.”

He added that Oregonians should keep in mind that “this is NOT just about ‘taxpayer funding’ it’s also forcing YOUR insurance, against [its] will, to include abortions in their coverage … and it’s a violation of the Weldon Act of Congress.”

Ms. Atteberry predicted the state’s abortion rate would climb as a result of the law.

“Oregon taxpayers already cover nearly 50 percent of all abortions in the state whether they like it or not,” said Ms. Atteberry. “By making abortion free, this percentage will inevitably increase. We also expect more late-term abortions, which are currently very expensive as well as risky to perform. All completely covered by either insurance companies or by the Oregon taxpayers.”