Department spokesman Joseph Ammerman says Chaney sent the plan Wednesday to the U.S. Department of Health and Human Services.
Chaney has steadily worked toward the creation of the online marketplace for people to buy insurance despite pressure from Gov. Phil Bryant and others to abandon the plan.
States faced a Friday deadline to send in their plans, or otherwise the federal government would set up exchanges for each state.
Chaney says he's no fan of the new federal health care law, but says Mississippi would be better off controlling its own exchange. Opponents say the state won't have enough freedom and Mississippi should have no association with a law they find odious.