Medi-Cal gets 50% of its funding from Medicaid. California claims the money is separate, but since money is fungible, the federal money can be counted towards money spent on illegal aliens.
It's not a fixed chunk of money going into a pot labeled "medi-cal" that gets disbursed (where fungibility would be a very reasonable argument), but literally cost sharing the services associated with the eligible enrollees in each state.
Talking about the common case here, what happens is that the MCOs take money from the state to provide services based on enrollment data. The state takes the enrollment data, divides it up into "federally eligible" and "non-eligible" populations, then splits the costs of the eligible population with the federal government and pays the rest themselves. If more "non-eligible" people get services, the federal share of medicaid payments for MCOs doesn't go up.
Some of the other payments like disproportionate share support the facilities themselves, which undocumented immigrants indirectly benefit from by virtue of use. That's not a significant percentage of the overall though and not what anyone is talking about.
Talking about the common case here, what happens is that the MCOs take money from the state to provide services based on enrollment data. The state takes the enrollment data, divides it up into "federally eligible" and "non-eligible" populations, then splits the costs of the eligible population with the federal government and pays the rest themselves. If more "non-eligible" people get services, the federal share of medicaid payments for MCOs doesn't go up.
Some of the other payments like disproportionate share support the facilities themselves, which undocumented immigrants indirectly benefit from by virtue of use. That's not a significant percentage of the overall though and not what anyone is talking about.