JEFFERSON CITY, Mo. -- A lawsuit was filed against the state on Friday over changes to Missouri's Medicaid program that goes into effect Tuesday.

Missouri Protection and Advocacy Services filed the lawsuit in Jackson County Circuit Court against the state Department of Social Services and the state Division of Medical Services.

The lawsuit alleges the changes in Medicaid are unlawful and would adversely impact about 20,000 Missourians.

Officials at the Department of Social Services and the Division of Medical Services were not available for comment on the lawsuit late Friday afternoon.

At issue is the state's Medicaid "spend-down provision" that allows people with higher incomes to qualify if their medical expenses reduce their available income to 74 percent of the federal poverty level -- $6,562 annually for an individual.

To qualify for Medicaid, most single adults can earn no more than 77 percent of the federal poverty level, or about $6,828 annually.

More than a week ago, Gov. Bob Holden announced the state was raising Medicaid's income cutoff for the disabled, blind and elderly to 80 percent of the federal poverty level -- about $7,094 annually for an individual.