Gov. Jay Nixon wants to know what modifications to Missouri's Medicaid system may be acceptable to federal health care officials.

Nixon was talking Tuesday with Health and Human Services Secretary Kathleen Sebelius about a potential Medicaid expansion. Specifically, Nixon wants to know how much flexibility Missouri has to make market-based changes or require co-payments from adults earning up to 138 percent of the poverty level, which is about $27,000 annually for a family of three.

Sebelius has said previously that states must expand Medicaid to that level to qualify for full federal funding.

Nixon also met Tuesday with state senators about a Medicaid expansion and rallied with disabled advocates at the Capitol in support of greater Medicaid coverage.

Missouri's Republican lawmakers have been reluctant to embrace the Medicaid expansion.