Colbey Ricklefs, MD
Colbey Ricklefs, MD is a Pediatric Adolescent Medicine Physician in San Francisco, CA, registered under NPI 1053948257. This provider registers 2 separate taxonomy codes, which usually means they practise across more than one recognised specialty.
Getting there
The practice address on file is 1975 4TH ST, San Francisco, CA 94143. We have not yet mapped what surrounds this office — parking, transit, and nearby pharmacies are added as our data collection reaches each location.
Credentials and Medicare
| Licence | State | Specialty |
|---|---|---|
| A185610 | CA | Pediatric Adolescent Medicine Physician primary |
This provider holds licence A185610 issued in CA. A licence number in NPPES reflects what was filed at registration — it does not confirm the licence is still active today.
This NPI does not appear in the PECOS Medicare enrolment file. Providers who do not bill Medicare — or who bill only through a group's enrolment — will not appear here. It is not a sign of any problem with the registration.
What Adolescent Medicine covers
A pediatrician who specializes in adolescent medicine is a multi-disciplinary healthcare specialist trained in the unique physical, psychological and social characteristics of adolescents, their healthcare problems and needs. NUCC Health Care Provider Taxonomy, code 2080A0000X
All registered taxonomy codes
This provider registers 2 taxonomy codes. The primary code is what appears on most claims; the others record additional recognised specialties.
| Code | Specialty | Licence | State | |
|---|---|---|---|---|
| 2080A0000X | Pediatric Adolescent Medicine Physician Adolescent Medicine | A185610 | CA | primary |
| 390200000X | Student in an Organized Health Care Education/Training Program | — | — |
The taxonomy records how the provider classifies their own practice. It does not confirm which conditions they currently treat, whether they are accepting new patients, or which insurance they take — call the office for that.
Full NPPES record
An NPI-1 identifies a single person. It stays with the clinician for life, even if they move practice or change state, which is why the address on file can lag behind where they actually work today.
| NPI | 1053948257 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Mar 26, 2020 |
| Last updated | Apr 22, 2026 |
| Status | Active |
| Sole proprietor | No |
| Credential | MD |
| Practice address |
1975 4TH ST San Francisco, CA 94143 (415) 353-2002 |
| Mailing address |
550 16TH ST # 110 San Francisco, CA 94143 |
Number check
How the check works, step by step
Every NPI carries a Luhn check digit — the same scheme used on credit cards. CMS prefixes the number with 80840 before computing it, which marks it as a US health identifier.
| Digit | 8 | 0 | 8 | 4 | 0 | 1 | 0 | 5 | 3 | 9 | 4 | 8 | 2 | 5 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 0 | 1 | 3 | 9 | 4 | 7 | 2 | 1 |
Sum = 53 · next multiple of 10 = 60 · check digit = 7 · actual last digit = 7
A valid check digit only means the number is well-formed. It does not mean the provider is licensed, active, or in good standing — those are separate questions answered by the sections above.