CMS CCN lookup and decoder.

What a CCN is

The CMS Certification Number, or CCN, is the identifier the Centers for Medicare and Medicaid Services uses for each provider or supplier that participates in Medicare or Medicaid. Chapter 2 of the State Operations Manual, section 2779A, says the CCN replaced the older terms Medicare Provider Number, Medicare Identification Number and OSCAR number effective in 2007, and that it is used to verify Medicare and Medicaid certification for survey and certification, assessment-related activities and communications. The regional office, not the State Agency or a Medicare contractor, assigns it.

Because the number is built from rules, a CCN tells you two things without any lookup: which State the facility is in, and what kind of facility it is. This page applies those rules to the number you hold. It does not search CMS data, so it will not tell you the facility's name or address; for that, use CMS's provider data.

How the six characters are built

Section 2779A1 states that the CCN for providers and suppliers paid under Medicare Part A has six digits: the first two identify the State, and the last four identify the type of facility. The manual's own list of State codes includes alphanumeric entries such as A0, B7 and E3. The manual explains why: once the pool of two-digit numeric codes is exhausted, CMS moves to alphanumeric two-character codes running from A0 through Z9. A new State code is only to be used once all the existing numbers in each CCN range for a facility type have been assigned. That is why a large State carries several codes, and why two hospitals in the same State can have different first two characters.

The last four digits are assigned sequentially within the range for the facility type. A short-term hospital gets a number between 0001 and 0879; a skilled nursing facility gets one between 5000 and 6499. Several types have a second, continuation range once the first fills up, for example home health agencies, which run 3100-3199, then 7000-8499, then 9000-9799.

Worked examples

All numbers below are made up; they are chosen only to show how the decoding works.

• 450001: State code 45 is Texas, and 0001 falls in 0001-0879, short-term hospitals.
• 221301: 22 is Massachusetts and 1301 falls in 1300-1399, critical access hospitals.
• 335050: 33 is New York and 5050 falls in 5000-6499, skilled nursing facilities.
• 05P123: the manual gives organ procurement organizations a letter P in the third position and a three-digit facility number, so this decodes as an organ procurement organization in California (code 05).
• 600001 fails: 60 is not on the State code list.
• 45001 fails on length, and the message points out that a spreadsheet may have dropped a leading zero: Alabama's 010001 turns into 10001 when stored as a number, because State codes 01 to 09 start with zero.
• 450000 fails because no range starts at 0000.

Facility type ranges

These are the ranges listed in section 2779A1 of the manual as it stood when we retrieved it. Where the manual notes an additional range for the same type, it is shown in brackets.

State codes

The same section lists every State code. A State's first code is the one assigned originally; later codes were added as ranges filled.

Edge cases and common mistakes

• Ten characters. A ten-character value with a letter in the third position is the Part B supplier layout in section 2779A2 (for example C for ambulatory surgical centers), not a provider CCN. The manual also notes that CLIA numbers keep being used for fee and certificate issuance. See the DEA and NPI checkers for other health identifiers.
• Leading zeros. State codes 01 to 09 start with zero, and spreadsheets strip it from numbers. Keep CCNs as text.
• Overlapping ranges. Some facility types have more than one range, so the same last four digits are never enough to name a type outside the table above.
• Type, not size or owner. The last four digits say what kind of facility it is. They say nothing about size, ownership, quality or payment.

Anyone working with provider identifiers may also want the NUCC taxonomy code lookup, the Medicare MBI validator for the patient-side number, and the FDA FEI validator for establishments FDA inspects.

Who this is for

Billing and revenue-cycle staff, analysts working with CMS cost reports and quality files, health policy researchers, and anyone matching facility records across spreadsheets who needs to know what a CCN prefix and suffix represent.

What this does not cover

• The facility's name, address, ownership, ratings or certification dates.
• Whether the number was assigned, active or retired. Ranges marked as retired or reserved in the table are described as the manual describes them.
• Medicaid-only provider numbers, Part B supplier numbers, NPIs and CLIA numbers.
• Changes CMS has made to the manual after the revision listed under Sources.

Why the check stays on your device

Nothing here needs a server. The decoder compares the characters you type with the State code list and ranges above, which are built into the page.

Sources

• CMS, State Operations Manual chapter 2, sections 2779A to 2779A2 (CCN layout, State codes, ranges; section 2779A1 is Rev. 226) (retrieved 2026-10)
• CMS, Provider Data Catalog (where CMS publishes facility data) (retrieved 2026-10)