South Dakota voters will decide Tuesday, Nov. 3, whether the state’s voter-approved Medicaid expansion should remain guaranteed in the state constitution only as long as Washington keeps paying 90% of its cost. Amendment I would remove that guarantee if the federal share ever drops below 90%, according to Ballotpedia’s summary of the measure.

The vote will not change anyone’s coverage on Wednesday morning under either outcome. The federal government currently pays 90% of South Dakota’s expansion costs, so the trigger would not be met today. The question is what happens later if Congress cuts that rate.

For more than 31,000 low-income South Dakotans, that future question is personal. Many rely on expansion coverage for checkups, prescriptions, and hospital care, and the rural hospitals that treat them have a direct stake in the outcome.

Coverage Built by a 2022 Vote

Voters approved Amendment D on Nov. 8, 2022, with about 56% support. It required the state to cover adults ages 18 to 64 with incomes up to 138% of the federal poverty level, roughly $1,800 a month for a single person in 2025, according to Ballotpedia. Because the expansion is written into the constitution, only voters can change it.

As of August 2026, more than 31,000 people were enrolled in expanded Medicaid, out of about 143,000 total Medicaid enrollees, according to South Dakota Department of Social Services data cited by South Dakota Searchlight. Becker’s Hospital Review noted that both sides put expansion enrollment at about 30,000.

The Legislature placed Amendment I on the ballot in 2025. The House passed it 59-7 on Jan. 21, 2025, and the Senate approved it 31-3 on March 3, 2025, with Republicans largely in support and Democrats opposed.

A Dispute Over What a Yes Vote Does

The sharpest disagreement is not about the 90% figure but about what happens if it falls. Attorney General Marty Jackley’s official ballot explanation says the amendment would end expanded coverage if federal funding drops below 90%, with eligibility returning to the groups covered before 2022: low-income children, pregnant women, people with disabilities, and older adults.

The measure’s sponsors reject that reading. Rep. Will Mortenson (R-Fort Pierre) called the title and explanation “100% inaccurate,” arguing the amendment only removes the constitutional requirement and leaves lawmakers free to keep, change, or repeal expansion. “It would absolutely not immediately remove Medicaid coverage for the expansion population,” he told Searchlight. Lt. Gov. Tony Venhuizen, an original sponsor, also disputed the ballot language.

Tim Rave, a former Republican legislator who now leads the South Dakota Association of Healthcare Organizations, reads it differently. “It says it will end if the federal match changes, period,” he said. Jackley has stood by the language, saying it follows the resolution’s wording.

That unresolved question matters for households. If the trigger were ever met, enrollees could face either an automatic end to coverage or a legislative debate, depending on whose reading prevails.

Budget Protection or Coverage Risk

Supporters frame Amendment I as a fiscal safeguard. Sen. Casey Crabtree (R-Madison), the Senate sponsor, said it “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.”

Lawmakers have estimated that if the federal share fell to 70%, the state would owe about $72 million to sustain expansion, which could force cuts elsewhere in the budget. The Republican Party of South Dakota and Americans for Tax Reform back the measure.

Opponents argue 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. “You’re betting on the come, so to speak, what’s that change going to be?” she said. Deb Fischer-Clemens, president of the South Dakota Nurses Association, warned that “there are hospitals in South Dakota that are very much balancing on the edge.”

Rave has said about $400 million a year flows to hospitals, clinics, and other providers through expansion, money for care that would otherwise likely go unpaid, which is a major concern for rural facilities. AARP South Dakota, which opposes the measure, said “taking away health coverage does not make those challenges disappear. It makes them worse.” The state Democratic Party, Change Agents of South Dakota, and Republican state Sen. Tom Pischke also oppose it, according to Ballotpedia.

An Oct. 19-21 Emerson College/KELOLAND poll of 803 likely voters found 26.9% supporting Amendment I, 59.4% opposed, and 13.7% undecided, according to Ballotpedia.

Federal Funding Pressures to Watch

The 90% rate is set by the Affordable Care Act, and it was not cut by the 2025 federal budget law known as the One Big Beautiful Bill Act. One narrow change took effect Oct. 1: the enhanced 90% match no longer applies to emergency Medicaid for noncitizens who are otherwise ineligible because of immigration status, according to the American Medical Association. That change does not affect the main expansion group, and no source reviewed said it would activate Amendment I.

Proposals to lower the expansion match have surfaced before. In 2024, the conservative Paragon Health Institute proposed phasing the 90% rate down toward each state’s regular match, KFF Health News reported. Nine states, including Arizona, Illinois, North Carolina, and Virginia, already have trigger laws that would end or scale back expansion if federal funding falls. No such cut is currently law.

Separately, the state estimates about 1,213 South Dakotans could lose expansion coverage when federal work requirements take effect next year, a change unrelated to Tuesday’s vote.

Expansion enrollees do not need to act because of the election. Anyone who receives a renewal or work-reporting notice from the Department of Social Services should respond by the deadline to avoid a coverage gap. Polls close at 7 p.m. local time Tuesday.

Whatever the result, the 90% match remains in place for now. The bigger test would come only if Congress changes it, and voters are deciding Tuesday who gets the final word when that happens.

Key Questions Answered

What is South Dakota Amendment I? It is a legislatively referred constitutional amendment that would remove the state’s guarantee of Medicaid expansion if federal funding falls below 90% of the cost.

Will anyone lose Medicaid coverage if Amendment I passes Tuesday? Not immediately. The federal government currently pays 90% of expansion costs, so the trigger would not be met unless Congress lowers that rate.

Who is covered by South Dakota’s Medicaid expansion? Adults ages 18 to 64 with incomes up to 138% of the federal poverty level. More than 31,000 people were enrolled as of August 2026.

Would coverage end automatically if the federal match dropped? That is disputed. The attorney general’s explanation says coverage would end, while sponsors say lawmakers would then decide whether to keep, change, or repeal expansion.

Who supports and opposes the measure? Republican legislative sponsors, the state Republican Party, and Americans for Tax Reform support it. AARP South Dakota, the state nurses association president, the state Democratic Party, Change Agents of South Dakota, and Republican Sen. Tom Pischke oppose it.

Do expansion enrollees need to do anything now? No action is needed because of the vote. Enrollees should still respond to any renewal or work-requirement notices from the Department of Social Services.

Published by Medicaldaily.com