ObamaCare expanded Medicaid to able-bodied adults below 138 percent of the federal poverty level. The expansion has been very costly to federal taxpayers particularly because the federal government covers a much larger share of costs for expansion enrollees than for enrollees in the older program. So far, 31 states have implemented the Medicaid expansion, while 19 have declined.

Republicans have long promised to repeal Obamacare. But the House Republican leadership’s new health bill would not even start to repeal ObamaCare’s Medicaid expansion until 2020, more than two and a half years from now, and even then would repeal it only one enrollee at a time. In 2020, states could no longer enroll new able-bodied adults into the Medicaid expansion. Yet the federal government would continue to pay for each and every continuously covered able-bodied adult who enrolled in the expansion before then. And it would do so at the enhanced ObamaCare matching rate, in perpetuity, until an enrollee leaves the program. If the House leadership has its way, we may be decades away from full repeal of the Medicaid expansion.

For the two-plus years between enactment and 2020, the House leadership bill would continue to allow states both to opt into the expansion and to go on an enrollment binge, for which the federal government could be paying for decades. It is likely that the number of states participating, and the number of people enrolled in the Medicaid expansion will be higher after “repeal” than before.

This means the Medicaid expansion may never disappear at all. By 2020, the constituency for preserving the Medicaid expansion would be much larger than it is now. More states, more voters, and more special interests will resist repealing the expansion than do today.

When eventually we see a Congressional Budget Office score of the bill (House leadership has numbers, but they’re not sharing them), it may show a reduction in federal spending on the Medicaid expansion after 2020. I would not bet on that happening.

The House leadership bill would also change the structure of Medicaid subsidies to the states. Currently, Congress matches states’ spending on their Medicaid programs. When a state spends $1 on its program, Congress contributes between $1 and $3. This creates a pay-for-dependence incentive. It encourages states to expand both enrollment and benefits far beyond what they would if states bore the full marginal cost.

The leadership bill would reform the Medicaid program by converting it to a system of “per capita block grants.” It would give each state a fixed amount of money per enrollee, with the amount varying by the type of enrollee (aged, blind, disabled, children, non-expansion adults, and expansion adults).

A per-capita block grant would therefore resemble ObamaCare’s Medicaid expansion. States would get additional federal dollars for each additional person they enroll in their programs. But states would face the full marginal cost of providing new or existing benefits to enrollees.

Just as ObamaCare’s Medicaid expansion created incentives for states to expand their programs to able-bodied adults, while reducing access to care for the aged, blind, disabled, children, and pregnant women, the House leadership bill would create (or preserve) an incentive to expand enrollment to less vulnerable populations while cutting benefits for more vulnerable populations.

For more on the new House bill, see here.