Definition
CMS Certification Number (CCN)
A CMS Certification Number (CCN) is the identifier CMS assigns to a provider certified to participate in Medicare or Medicaid, such as a hospital, nursing home or home health agency. The standard six-character format encodes the state and facility type.
2 min readReviewed September 14, 2026
Also known as: Medicare provider number, OSCAR number, Medicare certification number, CMS provider number
Key facts
- Assigned by
- CMS, when a facility is certified for Medicare or Medicaid
- Former names
- Medicare provider number, OSCAR number
- Standard format
- 6 characters: 2-digit state code plus 4-digit sequence number
- Type encoding
- Sequence ranges identify facility type, such as 0001 to 0879 for acute hospitals
- Used in
- Medicare cost reports, Care Compare data and survey records
What is a CMS Certification Number?
When a state survey agency or accrediting organization finds that a facility meets federal standards and CMS enters into a provider agreement, the facility receives a CCN. The number identifies the certified entity across CMS certification, survey, cost report and quality data.
A CCN is not an NPI. The National Provider Identifier (NPI) is the HIPAA standard identifier used on claims by any health care provider, while the CCN identifies a Medicare or Medicaid certification. A hospital can have several NPIs under one CCN, and an NPI alone does not reveal a facility's certification type.
Hospital units paid under a different Medicare system receive their own CCN in which a letter replaces the third character, for example S for a psychiatric unit and T for a rehabilitation unit.
How a CCN is structured
In a standard CCN, the first two digits are a state code (for example 05 for California, 33 for New York and 45 for Texas) and the last four digits fall in ranges reserved for facility types. Common hospital ranges include:
- 0001 to 0879: short-term acute care hospitals
- 1300 to 1399: Critical Access Hospitals
- 2000 to 2299: long-term care hospitals
- 3025 to 3099: rehabilitation hospitals
- 3300 to 3399: children's hospitals
- 4000 to 4499: psychiatric hospitals
Why the CCN matters
The CCN is the backbone of facility-level federal data:
- It joins CMS facility datasets: Care Compare quality measures and star ratings, cost reports, ownership files and payment program results.
- The number range lets analysts classify facilities without a separate lookup, for example separating Critical Access Hospitals from acute care hospitals.
- A CCN usually stays with a facility through a change of ownership when the new owner accepts assignment of the existing Medicare provider agreement, so ownership history must be tracked separately.
- Linking CCNs to NPIs, addresses and parent organizations connects facility quality and cost data to provider and prescribing data.