South Dakota voters reject Medicaid expansion trigger amendment

South Dakota voters on Tuesday rejected a constitutional amendment that could have ended the state’s Medicaid expansion if the federal government’s share of the program’s cost fell below 90%, South Dakota Searchlight reported.

Amendment I failed by approximately 56% to 44%, with approximately 165,000 votes against and 131,000 in favor in unofficial returns. The Associated Press called the race early Wednesday morning. Official results are expected next week.

The result keeps in place the Medicaid expansion that voters added to the state constitution in 2022 through Amendment D, a citizen-initiated measure. That amendment extended eligibility to adults with incomes up to 138% of the federal poverty level, adding them to traditional coverage groups such as children, older adults and people with disabilities.

Under federal law, the federal government pays 90% of the cost of covering the expansion population, according to KELOLAND. South Dakota’s Republican-controlled Legislature had declined that offer, first made during the Obama administration, before voters approved expansion directly.

What Amendment I would have changed

The Legislature voted in 2025 to send Amendment I to the ballot. Its sponsor, Rep. Will Mortenson, R-Fort Pierre, said the measure would let lawmakers repeal, alter or maintain expansion if the federal share dropped, rather than ending coverage outright.

In the state’s ballot question pamphlet, Mortenson, Lt. Gov. Tony Venhuizen and Republican lawmaker Casey Crabtree wrote that the amendment “would NOT automatically end Medicaid expansion.”

Attorney General Marty Jackley, also a Republican, wrote a ballot title and explanation stating that the amendment would end expanded coverage if federal funding dropped below 90%. Mortenson called that language “100% inaccurate,” South Dakota Searchlight reported.

Opponents, including Deb Fischer-Clemens, president of the South Dakota Nurses Association, argued that a no vote would protect coverage for roughly 30,000 residents. She said the amendment could end coverage immediately if federal funding slipped by even a fraction of a percent.

How much Medicaid expansion costs South Dakota

Approximately 31,000 of the roughly 143,000 South Dakotans enrolled in Medicaid are covered through expansion, according to the state Department of Social Services. From implementation through the end of the last state fiscal year in June, the state spent $76 million on expansion and received $870 million in federal expansion funding, the department reported.

After the vote, Mortenson said, “Fiscal policy is a tough sell on the ballot.” He said a larger state share of expansion costs could put schools, nursing homes and the state’s balanced budget at risk. Mortenson, who did not seek reelection this year, said he hopes the Legislature keeps watching the issue.

Opponents had warned that losing expansion could create financial challenges for hospitals, particularly rural facilities that depend on Medicaid to help cover patient care, KOTA TV reported.

What federal work requirements mean for South Dakota Medicaid expansion

The ballot result does not shield expansion enrollees from federal policy changes. The tax and spending law President Donald Trump signed in 2025 established work, school or community service requirements for expansion enrollees, which are expected to take effect next year. The Department of Social Services estimates that 1,213 South Dakotans could be disenrolled from expanded Medicaid once the requirements begin.

Voters also rejected Amendment L, which would have raised the threshold for approving constitutional amendments from a simple majority to 60%. Opponents argued the change was aimed at blocking voter-approved policies such as Medicaid expansion. Voters approved two other legislatively referred amendments, one specifying that only U.S. citizens may vote and another creating a trust fund for unclaimed property proceeds, according to MultiState.

Tim Rave, president and CEO of the South Dakota Association of Healthcare Organizations and a former Republican legislator, was among the health care leaders who opposed Amendment I.

“I think South Dakotans want to make sure that their fellow South Dakotans are taken care of, and they don’t want to face those medical debt challenges,” Rave said.