Matt Sparks, a spokesman for McCarthy, offered this explanation: “There are no changes until 2020. Then states will continue to receive the enhanced federal match for current enrollees.”

McCarthy’s claim hinges on the phrase “current enrollees.” The Congressional Budget Office, in its evaluation of the first version of the AHCA, said the reduction in funding would result in 14 million fewer Medicaid enrollees by 2026, a decline of about 17 percent compared with current law. Much of the decline would stem from the proposal’s termination of the enhanced federal match for new enrollees in states that choose to expand Medicaid, as well as a new per-person cap on federal payments to states. A new, lower federal match rate would apply to new enrollees after Dec. 31, 2019.

In any case, current enrollees are grandfathered in, right? Well, the problem is that people cycle in and out of Medicaid all the time, as they change or lose jobs. The CBO concluded that the reduction in spending would increase quickly as the grandfathered enrollees cycle off the program and are replaced by new enrollees. Indeed, historical data cited by the CBO indicated that fewer than one-third of those enrolled as of Dec. 31, 2019, "would have maintained continuous eligibility two years later."