Anita Choy, MD
Anita Choy, MD is an Allergy Physician in Palo Alto, CA, registered under NPI 1639136690. 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 1101 WELCH RD #A2, Palo Alto, CA 94304. 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 |
|---|---|---|
| A50663 | CA | Allergy Physician primary |
This provider holds licence A50663 issued in CA. A licence number in NPPES reflects what was filed at registration — it does not confirm the licence is still active today.
- Status
- Approved
- Provider type
- Practitioner - Allergy/immunology
- PAC ID
- 2264534577
- Enrollment ID
- I20070216000271
Medicare enrolment is recorded as approved under the provider type Practitioner - Allergy/immunology. Being enrolled means the provider can bill Medicare; it does not tell you whether they are currently accepting new Medicare patients. Call the office to confirm.
What Allergy covers
A physician who specializes in the diagnosis, treatment, and management of allergies. NUCC Health Care Provider Taxonomy, code 207KA0200X
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 | 1639136690 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Apr 26, 2006 |
| Last updated | Mar 7, 2023 |
| Status | Active |
| Sole proprietor | Yes |
| Gender | Female |
| Credential | MD |
| Practice address |
1101 WELCH RD #A2 Palo Alto, CA 94304 (650) 322-3847 Fax (650) 322-3249 |
| Mailing address |
211 QUARRY RD # 106 Palo Alto, CA 94304 |
| Other identifiers |
A50663
· Other (CA) |
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 | 3 | 9 | 1 | 3 | 6 | 6 | 9 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 6 | 6 | 9 | 2 | 3 | 3 | 6 | 9 |
Sum = 70 · next multiple of 10 = 70 · check digit = 0 · actual last digit = 0
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.