Apple’s initiative to enable iPhone users to securely access and carry their own medical records has continued to expand, as over 75 different health institutions are now supporting it — up from only 12 earlier this year. The company updated its list of medical partners ahead of a speech today by its Clinical and Health Informatics Lead Ricky Bloomfield, M.D., who offered insights into how the feature works for patients and providers.

Speaking at the ONC’s 2nd Interoperability Forum (via EHR Intelligence), Bloomfield said that Apple opted to support an open health data-sharing standard called Fast Healthcare Interoperability Resources (FHIR) that notably won’t be final until the end of this year. FHIR aggregates a patient’s health data from multiple sources, then makes it easy for the user to store, view, and share the data.

“You as a user have complete control over who has access to the data,” explained Bloomfield. “If you don’t want to share it, it won’t be shared. It stays private on your device until you decide to share it.” Bloomfield also said that Apple specifically selected the narrower Argonaut implementation of FHIR because it’s easier to use and will encourage greater adoption by medical providers.

As of this month, the iOS Health Records feature is supported by 77 different health systems representing hundreds of hospitals and clinics across the United States. Yet while Apple fully enables the feature in iOS, health records do not “traverse any Apple servers.” Instead, the iPhone makes a direct, secure connection to each health system to receive or send data. Whenever a new record becomes available from the health care provider, it’s automatically downloaded to the patient’s device — without the need for another sign-in, email notification, or other unnecessary friction.

On the viewing side, iOS users are able to use the Health app to see both the raw data that’s been transmitted and simple graphics that quickly illustrate whether a specific result is in or out of a proper range. Additional information stored on the device can include the user’s allergies, conditions, immunizations, labs, medications, procedures, and vital signs. All of the data is encrypted on the device, and available only when the user authenticates with a passcode.

Apple previewed the Health Records feature in January alongside the beta version of iOS 11.3, noting that the feature was in testing with a dozen primarily coastal and Midwestern U.S. health systems. In June, the company opened its Health Records API to let developers build apps with health history support, noting that patients were already using the feature at over 500 hospitals and clinics. Health Records is still listed as being in beta within the as-yet-unfinished iOS 12, but Apple has promised that third-party apps supporting the feature will debut this fall.

Regardless, a Capitol Hill briefing in April described Apple’s initiative as possibly “overhyped,” citing the limited data categories it transmits and its lack of Android support. Bloomfield’s speech today suggested that by incorporating the emerging open standard FHIR within its system, beginning with Argonaut implementation, it’s helping to prepare FHIR for even more widespread adoption in the very near future. While Apple-friendly health care systems will be in the lead, the same path could be followed by Android rivals that want to assist users with their health record needs.