House Republicans have the basic framework of an Obamacare replacement to show their constituents back home next week, but there’s no mention of the hardest part: How to pay for it.

In a 19-page memo sent to lawmakers Thursday, GOP leaders propose to shift Obamacare’s subsidies from income-based to age-based, gradually phase out Medicaid expansion and reshape its payments and expand the use of tax-free health savings accounts—all while repealing the Affordable Care Act’s taxes.