Derek Mafong, M.D.
NPI 1699781633 · Endocrinology, Diabetes & Metabolism Physician · San Diego, CA
Enrolled with Medicare as Practitioner - Endocrinology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Derek Mafong, M.D. is a Endocrinology, Diabetes & Metabolism Physician provider in San Diego, CA (NPI 1699781633).
Provider details
- NPI number
- 1699781633
- Entity type
- Individual
- Primary specialty
- Endocrinology, Diabetes & Metabolism PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- Yes
- License
- A89536 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure33% of score
19 yrs in NPPES registry
- Profile completeness33% of score
100% of core fields populated
- Practice footprint20% of score
1 documented practice location
- Open Payments transparency13% of score
Has Open Payments disclosures (2024)
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 · 28 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Levothyroxine Sodium | 218 | 82 |
| Methimazole | 158 | 56 |
| Semaglutidebrand: Ozempic | 117 | 17 |
| Alendronate Sodium | 53 | 22 |
| Teriparatidebrand: Forteo | 49 | 15 |
| Pen Needle, Diabeticbrand: Nano 2nd Gen Pen Needle | 46 | 27 |
| Insulin Glargine-Yfgn | 42 |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$10 across 1 record (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-07-31
- Last updated
- 2021-12-02
- Certified
- 2021-12-02
Frequently asked questions
- What is Derek Mafong's NPI number?
- Derek Mafong's National Provider Identifier (NPI) is 1699781633, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Derek Mafong's specialty?
- Derek Mafong is listed in the NPPES registry with a primary specialty of Endocrinology, Diabetes & Metabolism Physician (Allopathic & Osteopathic Physicians).
- Where is Derek Mafong located?
- Derek Mafong's practice location on file with NPPES is 200 W Arbor Dr, San Diego, CA 92103-9000.
- What is Derek Mafong's phone number?
- The practice phone number listed in the NPPES registry for Derek Mafong is (800) 926-8273.
- Does Derek Mafong accept Medicare?
- Derek Mafong is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Derek Mafong's NPI active?
- Yes — Derek Mafong's NPI (1699781633) is active in the NPPES registry as of the last update on 2021-12-02.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.