Dennis Buchanan, MD
NPI 1003864737 · Obstetrics & Gynecology Physician · Fullerton, CA
Enrolled with Medicare as Practitioner - Obstetrics/Gynecology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Dennis Buchanan, MD is a Obstetrics & Gynecology Physician provider in Fullerton, CA (NPI 1003864737).
Provider details
- NPI number
- 1003864737
- Entity type
- Individual
- Primary specialty
- Obstetrics & Gynecology PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- G42457 (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
20 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
99 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) |
|---|---|---|
| Cervical Or Vaginal Cancer Screening; Pelvic and Clinical Breast ExaminationG0101 | 43 | $42 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 37 | $97 |
| New Patient Office Or Other Outpatient Visit With Low Level of Medical Decision Making, If Using Time, 30 Minutes Or More99203 | 19 | $120 |
Typical Medicare-allowed amounts for these services range $42–$120 (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 · 9 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Estradiol | 89 | 32 |
| Clobetasol Propionate | 23 | 14 |
| Medroxyprogesterone Acetate | 19 | — |
| Estrogens, Conjugatedbrand: Premarin | 17 | — |
| Estradiolbrand: Estradiol (twice Weekly) | 15 | — |
| Estrogen,con/M-Progest Acetbrand: Prempro | 15 | — |
| Estradiolbrand: Estradiol (once Weekly) | 14 | — |
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-05-05
- Last updated
- 2021-10-15
- Certified
- 2021-10-15
Frequently asked questions
- What is Dennis Buchanan's NPI number?
- Dennis Buchanan's National Provider Identifier (NPI) is 1003864737, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Dennis Buchanan's specialty?
- Dennis Buchanan is listed in the NPPES registry with a primary specialty of Obstetrics & Gynecology Physician (Allopathic & Osteopathic Physicians).
- Where is Dennis Buchanan located?
- Dennis Buchanan's practice location on file with NPPES is 101 Laguna Rd Ste 100, Fullerton, CA 92835-3601.
- What is Dennis Buchanan's phone number?
- The practice phone number listed in the NPPES registry for Dennis Buchanan is (714) 992-5350.
- Does Dennis Buchanan accept Medicare?
- Dennis Buchanan is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Dennis Buchanan's NPI active?
- Yes — Dennis Buchanan's NPI (1003864737) is active in the NPPES registry as of the last update on 2021-10-15.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.