The Affordable Care Act opened new and expanded pathways to public health insurance coverage. Since 2014, many states have broadened their eligibility criteria for Medicaid, and have introduced new access points for Medicaid enrollment. During this time, publicly subsidized health insurance coverage also became available through state health insurance exchanges and through the federal health insurance marketplace. Recognizing there is a great deal to learn about who applies for and obtains these types of public coverage, the federal government and some states have established new data reporting efforts on how people use both new and existing pathways to health insurance coverage. In 2014 and 2015, Mathematica Policy Research supported the launch of such a reporting effort in California, with funding from the California Health Care Foundation. In this brief, we describe California's experience in reporting on applications, eligibility determinations, enrollments and coverage renewals for public insurance, highlight some of the practical implications of California's first few reports, and offer lessons for other states that are launching comparable reporting efforts. Key Findings: