Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of October 4, 2026.
NPIDirectory

Alexander F Castellanos, MD

Individual provider Family Medicine Physician · NPI 1770771511

Alexander F Castellanos, MD is registered under Family Practice in Templeton, California. Graduated from Stanford University School of Medicine in 1977, 49 years ago. Practices with David B. Hammer, a 116-clinician group and accepts Medicare assignment. Licensed in California.

Years since qualifying
49
Trained at
Stanford University School of Medicine
Licensed in
CA
In the registry since
2007
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

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Practice location Address checks out

699 S Main St
Templeton, CA 93465-5103 Not confirmed with CMS for 18 years — call before visiting
Phone: (805) 434-1804
Fax: (805) 434-1855
Show map & directions

Directions in Google Maps · Apple Maps · OpenStreetMap

Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Family Medicine Physician (primary) Taxonomy 207Q00000X · Licence G37303 (CA)

Record details

NPI number1770771511
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorYes
NPI enumeratedOctober 5, 2007
Last updated in NPPESDecember 26, 2007

Medicare enrollment

From the CMS Doctors & Clinicians file — this clinician is enrolled in Medicare.

Medicare specialtyFAMILY PRACTICE
Medical schoolSTANFORD UNIVERSITY SCHOOL OF MEDICINE
Graduated 1977 (49 years in practice)
Group practice David B. Hammer — 116 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
Practice locations2 on file with Medicare

Procedures

From CMS Care Compare, which counts the procedures a clinician billed to Original Medicare and Medicare Advantage over a recent 12-month period. CMS reports a fixed list of common procedures, so this is not everything the clinician does. Counts of 10 or fewer are given as a range, because CMS withholds small numbers.

Melanoma (skin cancer) excision 32 times · 81st percentile
Removal of skin lesions 64 times · 73rd percentile
Removal of nail tissue 1–10 times

The percentile compares how often this clinician performed the procedure with other clinicians who performed it, as CMS calculates it. It measures volume, not outcomes or skill.

Medicare patients and services, 2024

From the CMS Medicare Physician & Other Practitioners file for calendar year 2024. It counts Original Medicare patients only, so a practice that mostly sees Medicare Advantage or privately insured patients looks smaller here than it is.

Medicare patients277
Average patient age76

Dollar amounts are not shown. What Medicare pays a practice is gross billings, before staff, premises and tax and including the cost of any drugs it administers, so it is not what a clinician earns.

Payments from drug and device companies, 2025

Drug and device makers are required by federal law (the Physician Payments Sunshine Act) to report what they pay or give to clinicians, and CMS publishes the reports as Open Payments. This is the 2025 program year. A report is a record of a payment, not an allegation of anything, and many are small items such as meals. Only general payments are listed here; research payments and ownership or investment interests are reported separately by CMS and are not shown.

Food and Beverage $124 1 payment · a meal or drink at a meeting or visit, not a fee

Each amount is the sum of what companies reported for that kind of payment in 2025, rounded to the dollar. Not all of it is income to the clinician: a meal is not a fee, a charitable contribution goes to a charity, and a royalty or an acquisition payment is not a salary.

Check a report, or dispute one, at the source in CMS’s own tool, Open Payments. Corrections go through CMS’s dispute process. This site removes a home address on request and asks for no proof, because that is privacy; it will not remove an accurate payment report on request, because that is a statutory public disclosure.

Practises at

Facilities the CMS Facility Affiliation file lists for this clinician. Those with a page here are linked.

  • Central Coast Home Health Inc Home health agency · San Luis Obispo, CA · listed as Central Coast Home Health, Inc
  • Adventist Health Twin Cities Hospital · Templeton, CA
  • French Hospital Medical Center Hospital · San Luis Obispo, CA

Colleagues at David B. Hammer

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 116 clinicians in the practice; 12 are shown here.

Other providers in Templeton