The scale of Minnesota’s welfare fraud has stunned American taxpayers. “The largest Medicaid autism fraud case ever,” as put by the Justice Department, was among the schemes uncovered. The perpetrators built a yearslong operation that netted $46.6 million by exploiting autism therapy known as applied behavior analysis.The Centers for Medicare and Medicaid Services recently released a 173-page “tool kit” prompted by “the rapid growth in utilization and costs” of ABA and by many states’ “significant fiscal and oversight concerns.” Minnesota is hardly an aberration — as the CMS tool kit demonstrates, Medicaid ABA spending is compromised nationwide, not only in “the Land of 10,000 Frauds.”ABA subsidies suffer from an absence of postpayment verification of services combined with fluid definitions of what counts as “therapy.” This is a flaw of design, to which both federal and state guidelines contribute. Providers have every incentive to convert more minutes of purported therapy into revenue, and states have little incentive to police them. States administer funds supplied largely by taxpayers across the nation, imposing little discipline on their outlays. Parents whose children are insured by Medicaid incur no out-of-pocket costs for ineffective or never-occurring ABA treatment. If the state reimburses the cost of de facto babysitting, paying many times the going rate, parents are unlikely to object.