Iowa Gov. Terry Branstad is poised to become the ninth Republican governor to support expanding Medicaid under President Barack Obama 's health care reform law, the Dubuque Telegraph Herald reported Wednesday.

Branstad struck a deal with Republicans and Democrats in Iowa's divided Legislature Tuesday that caused him to reverse his prior opposition to adding more people to the joint federal-state health care program for the poor and people with disabilities, the Telegraph Herald reported , citing Iowa Senate President Pam Jochum (D).

Obama and the congressional Democrats who authored the health care reform law intended a major Medicaid expansion to provide coverage to millions of poor Americans, mostly working-age adults without children . But the Supreme Court ruling that upheld Obamacare last year also granted states the right to opt out of the expansion . With enrollment for next year beginning on Oct. 1, 2013, only about half of states appear likely to take up the expansion, meaning millions will continue to go without health benefits .

The health care reform law authorizes states to expand Medicaid to anyone whose income is below 133 percent of the poverty level, which is $15,282 for a single person this year. People who don't get health benefits from their jobs and earn between the poverty level, or $11,490 in 2013, and four times that amount can qualify for tax credits to offset the cost of private insurance.

The federal government will pay the full cost of expanding Medicaid from 2014 through 2016. That share will decline over several years until it reaches 90 percent in 2022 and beyond. The federal government currently pays an average of 57 percent of the costs for people on Medicaid. States don't face a deadline to decide on the expansion.

The Iowa proposal would offer the poorest residents Medicaid coverage while using federal Medicaid dollars to subsidize private insurance for people who earn between 101 percent and 133 percent of poverty, according to the Telegraph Herald.

Branstad strongly came out against the Medicaid expansion after the 2012 Supreme Court ruling, telling The Huffington Post last June, "We're opposed to it and we're not going to have any part of it."

In recent days, Iowa news outlets began reporting that Branstad had softened his resistance to the Medicaid expansion and indicated he could support a plan that protected the state from hypothetical cuts in federal Medicaid spending. Branstad and the Iowa House had devised a smaller Medicaid expansion that wouldn't have tapped full federal funding, but the state Senate voted it down it this month. Iowa officials were considering extending the legislative session to deal with the Medicaid issue.

Branstad's concerns about the Medicaid expansion are addressed in the deal with lawmakers , Tim Albrecht, a spokesman, told the Telegraph Herald. "This is a modernization of Medicaid and will serve both patients and taxpayers at a superior level," he said, according to the newspaper.

Republican governors, including John Kasich of Ohio and Rick Scott of Florida , have considered similar approaches, but have failed to win support from their Republican-controlled legislatures. The majority-Republican Legislature in Arkansas, however, joined with Democratic Gov. Mike Beebe last month to back a privatized version of the Medicaid expansion .

The chief executives of 28 states and the District of Columbia favor the Medicaid expansion, while about a dozen Republican governors remain opposed, according to an analysis by the Henry J. Kaiser Family Foundation. A handful of governors, including Scott and Missouri's Jay Nixon (D), have seen their Medicaid expansion plans die in their state legislatures.