Dennis J. Buchanan, MD
Obstetrics & Gynecology Physician · Fullerton, CA
Dennis J. Buchanan, MD is an obstetrics & gynecology physician with a practice address in Fullerton, California, and NPI 1003864737, issued on May 5, 2006. Check the license (California G42457, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Dennis J. Buchanan
- Credential
- MD
- Primary taxonomy
- Obstetrics & Gynecology Physician 207V00000X
- License number
- G42457 CA
Self-reported in NPPES; status is on the state search - Practice location
- 101 Laguna RD Ste 100, Fullerton, CA 92835
- Phone
- (714) 992-5350
- Enumerated
- May 5, 2006
- Record last updated
- Oct 15, 2021 (not updated in 5 years: call before relying on the address or phone)
- Fax
- (714) 992-8156
- Medicare enrollment
- Enrolled (PECOS I20100913000967); accepts Medicare assignment
- Medical or professional school
- University Of Southern California Keck School Of Medicine, 1979
- Entity
- Type 1 · individual
Also registered at 101 Laguna RD Ste 100
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Carla Betters, NPWomen's Health Nurse Practitioner1700258472
- Laura Biardi, CNMAdvanced Practice Midwife1639286792
- Christina BuchananObstetrics & Gynecology Physician1750818357
- Brian Gray, MDObstetrics & Gynecology Physician1457316705
- Cynthia Limon, PAPhysician Assistant1558009332
- Melody Opene, NPWomen's Health Nurse Practitioner1871961938
Verify Dennis J. Buchanan in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license G42457Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
84% more Medicare Part D claims than the average obstetrics & gynecology physician in 2024
304 Medicare Part D claims for 94 beneficiaries, against an average of 165 among the 28,733 providers of this specialty who prescribed in Part D. Brand-name drugs were 17% of claims.
Most prescribed
- Estradiol89 claims
- Clobetasol Propionate23 claims
- Medroxyprogesterone Acetate19 claims
- Premarin17 claims
- Estradiol (Twice Weekly)15 claims
- Prempro15 claims
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
Bills Medicare through one group practice
- Providence Medical FoundationFullerton, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Obstetrics & Gynecology Physician providers in California
There are 5,088 obstetrics & gynecology physician records in California.
Other obstetrics & gynecology physician records in California
- Ingrid Aalami, MDSan Jose, CA1952376550
- Avisa Abaian- Eagar, M.D.Orange, CA1316057755
- Derek Abbassi, MDWalnut Creek, CA1841364155
- Ahmed Abdelaziz, MDSanta Maria, CA1790039733
- Alireza Abdollah Shamshirsaz, M.D.Palo Alto, CA1881804235
- Nicole Abell, DOVentura, CA1811243603
- Zachary AbelsonLos Angeles, CA1689237414
- Ray Abinader, M.D.Loma Linda, CA1770901548
- Tarek Abou El Kheir, M.D.San Bernardino, CA1477521789
- Nada Abou-HaibaLos Angeles, CA1134067549
Common questions
What is Dennis J. Buchanan, MD's NPI number?
Dennis J. Buchanan, MD's National Provider Identifier (NPI) is 1003864737, issued on May 5, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Dennis J. Buchanan, MD located?
The NPPES record lists a practice address at 101 Laguna RD Ste 100, Fullerton, CA, 92835. Phone: (714) 992-5350. Providers update this record themselves, so call before visiting.
How can I verify Dennis J. Buchanan, MD's license?
NPPES lists California license number G42457, as entered by the provider. Search the Medical Board of California at https://www.mbc.ca.gov/License-Verification/default.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Dennis J. Buchanan, MD prescribe under Medicare Part D?
In 2024, Dennis J. Buchanan, MD had 304 Medicare Part D claims for 94 beneficiaries; the average among obstetrics & gynecology physician prescribers was 165. Part D covers Medicare prescriptions only.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.