The solution
India's health records lived in tens of thousands of disconnected hospital registers and paper files. The National Health Stack proposed by NITI Aayog in 2018 and the National Digital Health Blueprint sketched the opposite of a national database: shared rails. The National Digital Health Mission piloted from 15 August 2020 in six Union Territories and rolled out nationally as the Ayushman Bharat Digital Mission on 27 September 2021.
ABDM is three thin public rails. Registries give every citizen an ABHA number and every doctor and hospital a verified address. A consent manager stores data requests as signed, revocable artifacts the patient can audit. The exchange passes HL7 FHIR records between Health Information Providers and Users but keeps only indexes — files never leave the hospital that created them. Participation is voluntary, and identity, documents and e-signatures reuse Aadhaar, DigiLocker and eSign.
In practice the first mass habit was paperwork removal. Scan and Register lets a patient scan a QR code at the outpatient desk with any ABDM-enabled app, share their ABHA profile after giving consent, and get registered instantly — no forms, no queue. The National Health Authority reports the service crossed 25 crore registrations, running at about 4 lakh patients a day, across 30,800 facilities in 756 districts.
What it achieved
No central vault: registries + consent, records stay put
Why it worked
A central vault of 1.4 billion people's medical histories was politically and technically unbuildable; shared rails gave the state network effects without custody.
Consent as a signed, revocable object makes every access auditable — the design answer to the privacy objections that sank centralized health-ID schemes elsewhere.
Open standards (HL7 FHIR, SNOMED CT, DICOM) let existing hospital software join with a connector instead of a migration.
Reusing Aadhaar, DigiLocker and eSign meant identity, document and signature rails already existed — ABDM only had to build the health layer.
What can be applied
A state that wants a data network need not own the data. Registries, a consent switch and open standards let every hospital keep custody yet interoperate — UPI's playbook for medical files.
Aftermath
By March 2022 India had issued over 21 crore ABHA numbers, plus 6.1 crore more created through CoWIN; a 2024 Frontiers in Digital Health analysis counted more than 300 million health records linked to the system. Scan and Register alone crossed 25 crore outpatient registrations by August 2026, running at about 4 lakh patients a day across 30,800 public and private facilities. Hospitals join voluntarily; the National Health Authority's stated open problem is data quality, not infrastructure.
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