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ALEXANDER N GREINER M.D.
NPI 1609801299
Allergy & Immunology in San Diego, CA

Active since July 11, 2006PECOS EnrolledAccepts Medicare Assignment
5776 RUFFIN RD, SAN DIEGO, CA 92123(858) 292-1144(858) 268-5145 Get Directions Write a Review

NPPES record last updated: March 14, 2016. Verified against the NPPES registry weekly; last sync: October 25, 2026.

About Alexander N Greiner M.d. NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

ALEXANDER N GREINER M.D. (NPI 1609801299) is an individual allergy & immunology provider in San Diego, California, licensed in California (A77327) and active in the NPI registry since July 2006. He is enrolled in Medicare PECOS and is a graduate of State University Of Ny Upstate Medical University (1998).

NPPES Registry Identity

NPI1609801299
Entity TypeIndividualMale
Primary Taxonomy207K00000X
Provider Legal NameALEXANDER N GREINERCredential: M.D.
Location Address5776 RUFFIN RDSan Diego, CA 92123-1013
Mailing Address3020 Childrens Way, Mc5003San Diego, CA 92123-4223 · (858) 309-6300
Phone(858) 292-1144
Fax(858) 268-5145
Sole ProprietorNo
Medical School CMSState University Of Ny Upstate Medical UniversityGraduated 1998
Enumeration DateJuly 11, 2006
Last NPPES UpdateMarch 14, 2016
✔ NPI 1609801299 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtyAllergy & ImmunologyAllopathic & Osteopathic Physicians
Taxonomy Code207K00000X
License✔ Licensed in CA · A77327
Definition
An allergist-immunologist is trained in evaluation, physical and laboratory diagnosis, and management of disorders involving the immune system. Selected examples of such conditions include asthma, anaphylaxis, rhinitis, eczema, and adverse reactions to drugs, foods, and insect stings as well as immune deficiency diseases (both acquired and congenital), defects in host defense, and problems related to autoimmune disease, organ transplantation, or malignancies of the immune system.
Also ListedInternal MedicineTaxonomy 207R00000X · License A77327 (CA)
5776 RUFFIN RD, San Diego, CA 92123
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Other Identifiers 1

Medicare UPINH58490CA

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Alexander N Greiner M.d. is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.

PECOS PAC ID4486831682
PECOS Enrollment IDI20120515000549
Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Medicare Billing Reassignment

Medicare enrollment records show Alexander Greiner reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.

Rady Children's Hospital San Diego
3.2 mi
Pediatrics
3020 CHILDRENS WAY
San Diego, CA 92123
  • Reassigned Medicare billing, California enrollment
  • 562 clinicians in this Medicare group
NPI 1669617197 (858) 966-5911

Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Areas of Expertise CMS Part B claims

Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.

Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more 99214
This is a routine check-up for patients who have previously visited our clinic. It involves a comprehensive review of your health and any ongoing treatments. The consultation lasts between 30-39 minutes, allowing enough time to discuss any concerns.
23 services22 patients

Referred Medical Equipment & Supplies CMS DME claims

Durable medical equipment, devices and supplies this provider ordered from DME suppliers for patients, from Medicare fee-for-service claims.

Injection, immune globulin/hyaluronidase, (hyqvia), 100 mg immuneglobulin J1575
Treatment-Injections and Infusions (nononcologic) · category RI008N
1 supplier18 claims6,600 services$12.35 avg. paid by Medicare
Dollar amounts are the average Medicare paid the supplier per service. They are not the cost to the patient.

Other Providers at the Same Location NPPES 14

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

MRS. SAMANTHA BARBARA NIGRELLI-BARRIENTOS MSN, CPNP-PC
Nurse Practitioner (Pediatrics)
5776 RUFFIN RD
SAN DIEGO, CA 92123
San Diego County (858) 966-4900
MIKAELAH R. KUENHOLD FNP-C
Nurse Practitioner (Family)
5776 RUFFIN RD
SAN DIEGO, CA 92123
San Diego County (858) 292-1144
ELISE M. TETELMAN PA-C, MBA
Physician Assistant (Medical)
5776 RUFFIN RD
SAN DIEGO, CA 92123
San Diego County (858) 292-1144
DR. BOB GENG M.D.
Allergy & Immunology
5776 RUFFIN RD
SAN DIEGO, CA 92123
San Diego County (858) 292-1144
DR. SUSAN STEFANAC LAUBACH M.D.
Allergy & Immunology
5776 RUFFIN RD
SAN DIEGO, CA 92123
San Diego County (858) 292-1144
NANCY KAY OSTROM M.D.
Allergy & Immunology
5776 RUFFIN RD
SAN DIEGO, CA 92123
San Diego County (858) 292-1144
ALLERGY & ASTHMA MEDICAL GROUP & RESEARCH CENTER, A P.C.
Specialist
5776 RUFFIN RD
SAN DIEGO, CA 92123
San Diego County (858) 292-1144
MICHAEL JOSEPH WELCH M.D.
Allergy & Immunology
5776 RUFFIN RD
SAN DIEGO, CA 92123
San Diego County (858) 292-1144

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is Alexander Greiner's NPI number?

The NPI number for Alexander Greiner is 1609801299. It was assigned to this individual provider in the NPPES registry on July 11, 2006.

Where is Alexander Greiner located?

Alexander Greiner practices at 5776 Ruffin Rd, San Diego, CA 92123. The listed phone number is (858) 292-1144.

What is Alexander Greiner's specialty?

The primary specialty registered for this NPI is Allergy & Immunology with taxonomy code 207K00000X.

Is Alexander Greiner enrolled in Medicare?

Yes. Alexander Greiner is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.

Which organization bills Medicare for Alexander Greiner's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Alexander Greiner reassigns Medicare benefits to Rady Children's Hospital San Diego (San Diego, CA). The reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for Alexander Greiner's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

When was this NPI record last updated?

The NPPES record for Alexander Greiner was last updated on March 14, 2016. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 10 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.