Milestone 3 of the Ayushman Bharat Digital Mission is where your hospital stops only sharing records and starts consuming them. As a Health Information User (HIU), your clinicians can request a patient's records from any other ABDM-connected facility — with the patient's explicit consent.
The certification test cases focus on three things: raising a consent request with the correct purpose codes, handling consent grant and revocation callbacks gracefully, and rendering the received FHIR bundles in a clinically useful way.
Our advice after taking dozens of hospitals through the process: involve your doctors early. The technology is the easy part — the workflow change of checking external records during consultation is where adoption is won or lost.