Federal auditors have found $198 million in improper payments for Medicaid-funded autism services in four states, including Indiana, Wisconsin, Maine, and Colorado. The Department of Health and Human Services (HHS) found that another $410 million may have been incorrectly billed. The auditors examined 100 monthly bills in each state over a year and found potential payment errors. These errors were caused by carers billing for non-therapy time and during recreational activities and not keeping proper notes of the care. The federal government has requested the return of millions of dollars in improper payouts from each state. Since the introduction of new federal rules in 2014, Medicaid spending on Applied Behavior Analysis (ABA) therapy has increased by 298% nationwide.