Ann Phan, DO
NPI 1912526179 · Internal Medicine Physician · Fremont, CA
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Ann Phan, DO is a Internal Medicine Physician provider in Fremont, CA (NPI 1912526179).
Provider details
- NPI number
- 1912526179
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- DO
- Sex
- Female
- Sole proprietor
- No
- License
- 20A20914 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
6 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)28% of score
107 Medicare services, 2024 (ranked within specialty)
Medicare volume is ranked against active providers in the same specialty. Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 52 | $153 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 37 | $107 |
| Annual Wellness Visit, Includes a Personalized Prevention Plan of Service (pps), Subsequent VisitG0439 | 18 | $155 |
Typical Medicare-allowed amounts for these services range $107–$155 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, not a price quote and not what you would be billed. Medicare Part B covers roughly an eighth of all NPIs (65+ skew); services with fewer than 11 beneficiaries are suppressed by CMS. Source: CMS Medicare Physician & Other Practitioners, by Provider & Service.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 7 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Atorvastatin Calcium | 27 | 12 |
| Lisinopril | 23 | 11 |
| Amlodipine Besylate | 21 | — |
| Levothyroxine Sodium | 19 | — |
| Albuterol Sulfatebrand: Albuterol Sulfate Hfa | 13 | — |
| Hydrochlorothiazide | 12 | — |
| Pantoprazole Sodium |
Practice location
Mailing address
Registry dates
- Enumerated
- 2020-04-08
- Last updated
- 2024-03-18
- Certified
- 2024-03-18
Frequently asked questions
- What is Ann Phan's NPI number?
- Ann Phan's National Provider Identifier (NPI) is 1912526179, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Ann Phan's specialty?
- Ann Phan is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Ann Phan located?
- Ann Phan's practice location on file with NPPES is 3200 Kearney St, Fremont, CA 94538-2299.
- What is Ann Phan's phone number?
- The practice phone number listed in the NPPES registry for Ann Phan is (510) 490-1222.
- Does Ann Phan accept Medicare?
- Ann Phan is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Ann Phan's NPI active?
- Yes — Ann Phan's NPI (1912526179) is active in the NPPES registry as of the last update on 2024-03-18.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.