The Balanced Budget Act of August 1997 was intended to improve the insurance coverage of low-income children. Although no specific mandates for evaluation accompanied the legislation, states are expected to assess its impact. Insurance improves access to and use of health services. The extent to which this is associated with better health depends on the kinds of services received. Access to a regular source of care is a critical characteristic. If this source of care provides good primary care, a variety of benefits would be expected to accrue. Thus, evaluation of the benefits of the State Children's Health Insurance Program should address not only improved coverage by health insurance for eligible children, but also the extent to which children receive high-quality primary care, including appropriate referrals when needed. Maternal access to and use of services is also a critical factor. Targets for evaluation include state activities to (a) enroll through outreach, inform through education, and develop information systems for tracking; (b) assess the degree of penetration of insurance among low-income children and their mothers, the availability of health care personnel, and the adequacy of benefits conferred by the insurance, primary-care services, and back-up specialty services; and (c) obtain evidence of improved health status. This article details approaches that can appropriately be used to address each of these aspects of concern.