Illinois health plans frequently deny coverage of mental health and addiction care according to a survey of behavioral health professionals and provider organizations in the state. Although all Medicaid managed care organization (MCO) plans and nearly all commercial insurance plans are required to cover mental health and addiction treatment at parity with general medical/surgical benefits, the survey found that a majority of behavioral health professionals reported the requested level of care for behavioral health treatment is sometimes/often/or always denied, and the plans refuse to provide medical necessity criteria. For inpatient treatment, about 59% of respondents reported that . . .