David Chang, M.D.
NPI 1639330806 · Internal Medicine Physician · Stanford, CA
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
David Chang, M.D. is a Internal Medicine Physician provider in Stanford, CA (NPI 1639330806).
Provider details
- NPI number
- 1639330806
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- C149397 (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
18 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
3 documented practice locations
- Medicare service volume (vs. specialty peers)28% of score
203 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 Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 90 | $75 |
| Annual Wellness Visit, Includes a Personalized Prevention Plan of Service (pps), Subsequent VisitG0439 | 55 | $71 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 39 | $90 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 19 | $94 |
Typical Medicare-allowed amounts for these services range $71–$94 (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 · 24 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Atorvastatin Calcium | 148 | 53 |
| Lisinopril | 64 | 23 |
| Amlodipine Besylate | 56 | 20 |
| Levothyroxine Sodium | 52 | 15 |
| Metformin Hcl | 51 | 17 |
| Losartan Potassium | 40 | 15 |
| Hydrochlorothiazide |
Practice location
Mailing address
Additional practice locations (2)
- 211 Quarry Rd Ste 305Palo Alto, CA 94304-1416Phone: (650) 498-9000Fax: (650) 498-9000
- 1701 High St Ste 102Portsmouth Health DepartmentPortsmouth, VA 23704-3103Phone: (804) 393-8585
Registry dates
- Enumerated
- 2008-06-20
- Last updated
- 2024-04-18
- Certified
- 2024-04-18
Frequently asked questions
- What is David Chang's NPI number?
- David Chang's National Provider Identifier (NPI) is 1639330806, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is David Chang's specialty?
- David Chang is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is David Chang located?
- David Chang's practice location on file with NPPES is 300 Pasteur Dr, Stanford, CA 94305-2200.
- What is David Chang's phone number?
- The practice phone number listed in the NPPES registry for David Chang is (650) 725-4000.
- Does David Chang accept Medicare?
- David Chang is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is David Chang's NPI active?
- Yes — David Chang's NPI (1639330806) is active in the NPPES registry as of the last update on 2024-04-18.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.