Tiffany Willingham, SUDRC
Tiffany Willingham, SUDRC is a Peer Specialist in Costa Mesa, CA, registered under NPI 1699507814. This provider registers 2 separate taxonomy codes, which usually means they practise across more than one recognised specialty. NPPES records them as a sole proprietor, meaning the practice is not incorporated as a separate legal entity.
Getting there
The practice address on file is 671 GOVERNOR ST, Costa Mesa, CA 92627. 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 |
|---|---|---|
| 18573 | CA | Peer Specialist primary |
This provider holds licence 18573 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 Peer Specialist covers
Individuals certified to perform peer support services through a training process defined by a government agency, such as the Department of Veterans Affairs or a state mental health department/certification/licensing authority. NUCC Health Care Provider Taxonomy, code 175T00000X
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 | |
|---|---|---|---|---|
| 175T00000X | Peer Specialist | 18573 | CA | primary |
| 101YA0400X | Addiction (Substance Use Disorder) Counselor Addiction (Substance Use Disorder) | — | — |
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 | 1699507814 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Aug 16, 2024 |
| Last updated | Dec 16, 2025 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | SUDRC |
| Practice address |
671 GOVERNOR ST Costa Mesa, CA 92627 (949) 343-6565 |
| Mailing address |
14400 NEWPORT AVE APT 91 Tustin, CA 92780 |
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 | 6 | 9 | 9 | 5 | 0 | 7 | 8 | 1 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 6 | 9 | 9 | 1 | 0 | 5 | 8 | 2 |
Sum = 66 · next multiple of 10 = 70 · check digit = 4 · actual last digit = 4
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.