The Office of the National Coordinator for Health Information Technology (ONC) released its proposed rule implementing provisions of the 21st Century Cures Act. Issues covered in the rulemaking include prohibitions against the blocking of data by providers or EHR vendors, the development and deployment of Application Programming Interface (API) standards, EHR developer certification, development of pediatric health information technology, practice ability to export patient data from one EHR to another, and other topics. Concurrently, the Centers for Medicare & Medicaid Services (CMS) issued a proposed rule on patient access to data using APIs, health information exchange across health plans, and other topics. Both agencies also included an RFI on the issue of accurately matching patient records. ONC and CMS will accept comments on these proposals until mid-April. MGMA will comment on each of these rules and the RFI.