Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of August 10, 2026.
NPIDirectory

Alexander N Greiner, MD

Individual provider Allergy & Immunology Physician · NPI 1609801299

Alexander N Greiner, MD practises Allergy/Immunology in San Diego, California. Graduated from State University of Ny Upstate Medical University in 1998, 28 years ago. Practices with Rady Children's Hospital San Diego, a 161-clinician group, accepts Medicare assignment and offers telehealth. Licensed in California.

Years since qualifying
28
Trained at
State University of Ny Upstate Medical University
Licensed in
CA
In the registry since
2006
Specialties on file
2
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

See every abbreviation used in this directory →

Claim this listing Report a problem Suggest an edit

Practice location Address checks out

5776 Ruffin Rd
San Diego, CA 92123-1013 Not confirmed with CMS for 10 years — call before visiting
Phone: (858) 292-1144
Fax: (858) 268-5145
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

Allergy & Immunology Physician (primary) Taxonomy 207K00000X · Licence A77327 (CA)
Internal Medicine Physician Taxonomy 207R00000X · Licence A77327 (CA)

Record details

NPI number1609801299
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedJuly 11, 2006
Last updated in NPPESMarch 14, 2016

Medicare enrollment

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

Medicare specialtyALLERGY/IMMUNOLOGY
Medical schoolSTATE UNIVERSITY OF NY UPSTATE MEDICAL UNIVERSITY
Graduated 1998 (28 years in practice)
Group practice Rady Children'S Hospital San Diego — 161 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
TelehealthOffers telehealth services
Practice locations4 on file with Medicare

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 patients42
Services billed 482 a service is one billed item, such as a visit, a test or a procedure
Average patient age74

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 $545 23 payments · 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.

Colleagues at Rady Children's Hospital San Diego

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 161 clinicians in the practice; 12 are shown here.

Other providers in San Diego