Recent initiatives to improve private insurance coverage for substance abuse and mental health in the United States have mostly focused on equalizing coverage limits to those found in general medical care. Federal law does not address cost sharing (copayments and coinsurance), which may also deter needed care or impose significant financial burdens on enrollees. This article reports on cost sharing requirements for outpatient care in a nationally representative sample of managed care plans in 1999. Levels of cost sharing are substantial, with around 40 percent of products requiring copayments of $20 or more and another 15 percent requiring coinsurance of 50 percent. Cost sharing for outpatient substance abuse treatment is very similar to that for mental health. Compared to general medical care, at least 30 percent of products impose higher cost sharing for substance abuse and mental health treatment. Future parity initiatives should be examined for how they address differences in cost sharing as well as limits.