as originally drafted the affordable care act required every state to expand its medicaid program for all adults up to 138% of the poverty level (roughly $15 900 in annual income for a single person household). prior to the affordable care act many states' medicaid programs covered only the poorest of the poor adults. complementing the medicaid expansion the affordable care act made federal subsidies available to people who made too much to qualify for medicaid but still had income low enough that insurance premiums were unaffordable. the supreme court struck down the requirement for states to expand medicaid and instead made it optional. there is still a significant incentive for states to expand - the federal government will pay all the costs of the expansion for the first 3 years - but a number of states have decided against the medicaid expansion. in those states people who are between 100% and 400% of the federal poverty level can still get a premium subsidy to buy a private policy but people below 100% and do not qualify for medicaid will not receive any assistance.
exactly what does it mean when states are not expanding medicaid?