adopted by States to collect health care claims data across different payers such as private insurers, government employee health plans, Medicare, and Medicaid. (9) APCD data can be shared with vetted and authorized users to make it easier to track trends in health care prices, create tools for consumers to check price and quality, assist employers and health plans in making more informed decisions when developing employer-sponsored health plans, test new ideas for holding down health care costs, and guide policymakers in developing health care policy. (10) In 2019, the independent, non-partisan RAND Corporation published the first broad-based study reporting prices paid by private health plans to hospitals identified by name. This important study tracked important disparities in price trends across the nation, with relative prices increasing rapidly from 2015 to 2017 for hospitals in some States, while falling in others. This work was made possible in part through the use of data from APCDs in New Hampshire and Colorado. (11) Since 2015, Oregon has used data from its APCD to review insurers’ proposed premium rates, including determining whether or not proposed premiums are excessive. Oregon has also used its APCD to create an annual report on hospital reimbursement variations from different insurers. (12) Minnesota and Virginia have used data from their APCDs to shine a spotlight on spending for low-value—possibly even unnecessary—medical services. (13) Washington State has used data from its APCD to create the Washington HealthCareCompare tool that helps patients learn about local prices for medical services at local doctors’ offices, hospitals, and outpatient centers, and puts those prices in context by highlighting what kinds of prices can be considered typical, low, or high. Additional States that have developed price transparency tools from their APCDs include New Hampshire, Maine, Massachusetts, Colorado, Maryland, and Rhode Island. (14) According to the APCD Council, a learning collaborative of public