Sharon Williams, M.D.
Sharon Williams, M.D. is an Allergy & Immunology Physician in North Tustin, CA, registered under NPI 1457772949. This provider registers 6 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 12231 NEWPORT AVE, North Tustin, CA 92705. 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 |
|---|---|---|
| A113432 | CA | Allergy & Immunology Physician primary |
| A133432 | CA | Clinical & Laboratory Immunology (Allergy… |
| A133432 | CA | Allergy Physician |
| A133432 | CA | Internal Medicine Physician |
| A133432 | CA | Allergy & Immunology (Internal Medicine)… |
| A133432 | CA | Pediatric Allergy/Immunology Physician |
This provider holds licence A113432 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 Allergy & Immunology covers
An allergist-immunologist is trained in evaluation, physical and laboratory diagnosis, and management of disorders involving the immune system. Selected examples of such conditions include asthma, anaphylaxis, rhinitis, eczema, and adverse reactions to drugs, foods, and insect stings as well as immune deficiency diseases (both acquired and congenital), defects in host defense, and problems related to autoimmune disease, organ transplantation, or malignancies of the immune system. NUCC Health Care Provider Taxonomy, code 207K00000X
All registered taxonomy codes
This provider registers 6 taxonomy codes. The primary code is what appears on most claims; the others record additional recognised specialties.
| Code | Specialty | Licence | State | |
|---|---|---|---|---|
| 207K00000X | Allergy & Immunology Physician | A113432 | CA | primary |
| 207KI0005X | Clinical & Laboratory Immunology (Allergy & Immunology) Physician Clinical & Laboratory Immunology | A133432 | CA | |
| 207KA0200X | Allergy Physician Allergy | A133432 | CA | |
| 207R00000X | Internal Medicine Physician | A133432 | CA | |
| 207RA0201X | Allergy & Immunology (Internal Medicine) Physician Allergy & Immunology | A133432 | CA | |
| 2080P0201X | Pediatric Allergy/Immunology Physician Pediatric Allergy/Immunology | A133432 | CA |
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 | 1457772949 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Dec 30, 2013 |
| Last updated | Mar 7, 2023 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | M.D. |
| Practice address |
12231 NEWPORT AVE North Tustin, CA 92705 (949) 519-2311 Fax (949) 276-3209 |
| Mailing address |
PO BOX 14107 Irvine, CA 92623 |
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 | 4 | 5 | 7 | 7 | 7 | 2 | 9 | 4 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 4 | 1 | 7 | 5 | 7 | 4 | 9 | 8 |
Sum = 71 · next multiple of 10 = 80 · check digit = 9 · actual last digit = 9
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.