South Dakota voters are deciding on Tuesday, November 3, 2026, whether the state’s voter-approved Medicaid expansion should remain guaranteed in the state constitution only as long as the federal government maintains its 90% cost-sharing match, medicaldaily.com reported. Should the federal portion ever fall under 90%, the measure’s Ballotpedia overview indicates that Amendment I would eliminate this protection.
The ballot measure will not alter anyone’s health insurance coverage on Wednesday morning regardless of the outcome. Because the federal government currently covers 90% of the program expenses, the trigger would not be met today. The core debate centers on future fiscal shifts and legislative control.
How the Expansion Took Shape
Voters originally established the program by approving Amendment D on November 8, 2022, passing it with roughly 56% of the vote. That constitutional change mandated state coverage for adults between the ages of 18 and 64 with incomes up to 138% of the federal poverty level, translating to about $1,800 a month for a single individual in 2025, according to Ballotpedia. Because the mandate lives in the state constitution, only voters can change it.
South Dakota: Amendment I could end Medicaid expansion if federal funding drops below 90%. Supporters cite fiscal flexibility; opponents say it undoes voters’ 2022 choice. Coverage is on ballots. Check your ballot. pic.twitter.com/gR8DXvMDNO
Department of Social Services data cited by South Dakota Searchlight shows that more than 31,000 people were enrolled in the expanded program as of August 2026, out of roughly 143,000 total Medicaid beneficiaries in the state. Becker’s Hospital Review similarly places expansion enrollment right around the 30,000 mark. The South Dakota Legislature subsequently placed Amendment I on the ballot in 2025, securing a 59-7 vote in the House on January 21 and a 31-3 approval in the Senate on March 3, with Republican lawmakers largely in support and Democrats opposed.
Disputing the Legal Fallout of a Yes Vote
The most intense disagreement surrounding Amendment I is not about the 90% benchmark itself, but about the legal mechanism triggered if federal funding eventually dips below that line. Based on the ballot explanation provided by Attorney General Marty Jackley, a drop in federal funding below 90% would terminate the expanded coverage and revert eligibility back to the categories included prior to 2022: older adults, people with disabilities, pregnant women, and low-income children.
Sponsors of the measure reject that interpretation. Rep. Will Mortenson (R-Fort Pierre) labeled the title and explanation “100% inaccurate,” arguing that the amendment only removes the constitutional requirement and leaves lawmakers free to choose whether to keep, change, or repeal the expansion. “It would absolutely not immediately remove Medicaid coverage for the expansion population,” Mortenson told South Dakota Searchlight. Lt. Gov. Tony Venhuizen, an original sponsor, also disputed the ballot language.
Other stakeholders read the text differently. Tim Rave, a former Republican legislator who now leads the South Dakota Association of Healthcare Organizations, stated, “It says it will end if the federal match changes, period.” Jackley has stood behind the official language, maintaining that it directly follows the phrasing of the legislative resolution.
South Dakota Republicans Put a Measure on Tuesday's Ballot That Would End Medicaid Expansion for 30,000 People If Washington Cuts Its Share https://t.co/nzDu6rMtpW
Budgetary Safeguards Versus Health Care Vulnerability
Supporters view Amendment I as a fiscal safeguard. Senate sponsor Sen. Casey Crabtree (R-Madison) said the measure “only acts if Washington breaks its original promise of supporting this with a 90% federal match,” Dakota News Now reported. He added that if Washington changes the deal, South Dakotans “shouldn’t automatically be stuck with a tax increase.” Legislative estimates indicate that if the federal share dropped to 70%, the state would owe about $72 million to sustain the expansion, which could force cuts elsewhere in the budget. The measure is backed by the Republican Party of South Dakota and Americans for Tax Reform.
Opponents contend the amendment is premature and puts coverage at risk over a cut that has not happened. Former lawmaker and nurse Jean Hunhoff questioned voting on a change that has not been made. AARP South Dakota, which opposes the amendment, said “taking away health coverage does not make those challenges disappear. It makes them worse.” Additional opposition comes from the state Democratic Party, Change Agents of South Dakota, and Republican state Sen. Tom Pischke, according to Ballotpedia. Ballotpedia reported that a survey conducted among 803 likely voters by Emerson College and KELOLAND from October 19 to 21 showed 26.9% backing Amendment I, 59.4% against it, and 13.7% undecided.
This November, South Dakota voters will decide on Constitutional Amendment I, a ballot measure that would repeal the state's Medicaid expansion if federal funding falls below 90 percent. SDPB breaks down the arguments for and against the proposed amendment in our 2026 Ballot… pic.twitter.com/WhcXxRYEKY
Federal Law Protects the Medicaid Expansion Rate
The 90% rate is set by the Affordable Care Act and was not cut by the 2025 federal budget law known as the One Big Beautiful Bill Act. According to data from the American Medical Association, a single specific modification took effect on October 1, halting the 90% enhanced matching rate for emergency Medicaid services provided to noncitizens who otherwise lack qualification due to their immigration status. That specific change does not activate the proposed amendment.
Looking at the national landscape as of May 2026, 12 states have implemented statutes—commonly called trigger laws—designed to automatically terminate or mandate a review of Medicaid expansion should federal contributions fall beneath a designated percentage. Within that group, eight states—Arizona, Arkansas, Illinois, Indiana, New Hampshire, North Carolina, Utah, and Virginia—maintain trigger statutes that mandate the complete termination of their Medicaid expansion programs if the federal cost-share drops past a specific limit.
