Katherine Tuan, M.D.
NPI 1588907315 · Internal Medicine Physician · Downey, CA
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Katherine Tuan, M.D. is a Internal Medicine Physician provider in Downey, CA (NPI 1588907315).
Provider details
- NPI number
- 1588907315
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Female
- Sole proprietor
- No
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Student, Health Care
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
13 yrs in NPPES registry
- Profile completeness38% of score
83% of core fields populated
- Practice footprint23% of score
1 documented practice location
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 prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 78 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Atorvastatin Calcium | 381 | 137 |
| Amlodipine Besylate | 323 | 118 |
| Losartan Potassium | 165 | 55 |
| Lisinopril | 147 | 61 |
| Levothyroxine Sodium | 137 | 43 |
| Metformin Hcl | 129 | 48 |
| Omeprazole |
Practice location
Mailing address
Registry dates
- Enumerated
- 2013-03-29
- Last updated
- 2021-11-29
Frequently asked questions
- What is Katherine Tuan's NPI number?
- Katherine Tuan's National Provider Identifier (NPI) is 1588907315, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Katherine Tuan's specialty?
- Katherine Tuan is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Katherine Tuan located?
- Katherine Tuan's practice location on file with NPPES is 9449 Imperial Hwy, Downey, CA 90242-2814.
- What is Katherine Tuan's phone number?
- The practice phone number listed in the NPPES registry for Katherine Tuan is (800) 823-4040.
- Does Katherine Tuan accept Medicare?
- Katherine Tuan is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Katherine Tuan's NPI active?
- Yes — Katherine Tuan's NPI (1588907315) is active in the NPPES registry as of the last update on 2021-11-29.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.