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DR. GREGORY JAMES ZAHNER MD
NPI 1427685767
Internal Medicine in San Francisco, CA

Active since March 26, 2020PECOS EnrolledAccepts Medicare Assignment
505 PARNASSUS AVE, SAN FRANCISCO, CA 94143(415) 476-1000 Get Directions Write a Review

NPPES record last updated: August 8, 2025. Verified against the NPPES registry weekly; last sync: August 16, 2026.

Record update history: Aug 8, 2025, May 15, 2023, Feb 7, 2022 and 1 more (4 updates tracked since 2020).

About Dr. Gregory James Zahner Md NPPES

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

DR. GREGORY JAMES ZAHNER MD (NPI 1427685767) is an individual internal medicine provider in San Francisco, California, licensed in California (A201693) and active in the NPI registry since March 2020. He is enrolled in Medicare PECOS and is a graduate of University Of California, San Francisco School Of Medicine (2020).

NPPES Registry Identity

NPI1427685767
Entity TypeIndividualMale
Primary Taxonomy207R00000X
Provider Legal NameDR. GREGORY JAMES ZAHNERCredential: MD
Location Address505 PARNASSUS AVESan Francisco, CA 94143-2204
Mailing Address505 Parnassus AveSan Francisco, CA 94143-2204 · (415) 476-1000
Phone(415) 476-1000
Sole ProprietorNo
Medical School CMSUniversity Of California, San Francisco School Of MedicineGraduated 2020
Enumeration DateMarch 26, 2020
Last NPPES UpdateAugust 8, 20254 updates tracked since enumeration
NPPES CertifiedAugust 8, 2025
✔ NPI 1427685767 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal MedicineAllopathic & Osteopathic Physicians
Taxonomy Code207R00000X
Licenses✔ Licensed in CA · A201693✔ Licensed in MA · 1013382
Definition
A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults and the elderly. Internists are trained in the diagnosis and treatment of cancer, infections and diseases affecting the heart, blood, kidneys, joints and digestive, respiratory and vascular systems. They are also trained in the essentials of primary care internal medicine, which incorporates an understanding of disease prevention, wellness, substance abuse, mental health and effective treatment of common problems of the eyes, ears, skin, nervous system and reproductive organs.
505 PARNASSUS AVE, San Francisco, CA 94143
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Medicare Participation & PECOS CMS

Medicare enrollment, assignment, and ordering and referring status from the CMS PECOS system.

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Dr. Gregory James Zahner Md 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 ID6406266253
PECOS Enrollment IDI20250625004143
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.

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 94143 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient
$153.83 typical visit price
range $69.00 – $202.35
Typical copayment $38.45 (range $17.25 – $50.58)
Most-billed visit code 99204
Established Patient
$119.48 typical visit price
range $23.44 – $166.46
Typical copayment $29.87 (range $5.86 – $41.61)
Most-billed visit code 99214
Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

Other Providers at the Same Location NPPES 20

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

CATHERINE RAMSDELL NNP
Nurse Practitioner (Neonatal)
505 PARNASSUS AVE
SAN FRANCISCO, CA 94143
San Francisco County (415) 353-1000
DR. CLAUDIO ANDRES BRAVO CARRILLO M.D.
Internal Medicine (Advanced Heart Failure and Transplant Cardiology)
505 PARNASSUS AVE
SAN FRANCISCO, CA 94143
San Francisco County (415) 502-4243
MAURICIO JALIFE BUCAY M.D
Hospitalist
505 PARNASSUS AVE
SAN FRANCISCO, CA 94143
San Francisco County (415) 750-4994
EMMA B SHAK M.D.
Student in an Organized Health Care Education/Training Program
505 PARNASSUS AVE
SAN FRANCISCO, CA 94143
San Francisco County (415) 476-1528
DR. ADRIANA A.T. MARTIN M.D., PH.D.
Internal Medicine
505 PARNASSUS AVE
SAN FRANCISCO, CA 94143
San Francisco County (415) 514-7288
WILLIAM JAMES DEARDORFF
Internal Medicine (Geriatric Medicine)
505 PARNASSUS AVE, 15 LONG
SAN FRANCISCO, CA 94143
San Francisco County (415) 406-1417
KEERTHANA REDDY BANALA
Student in an Organized Health Care Education/Training Program
505 PARNASSUS AVE
SAN FRANCISCO, CA 94143
San Francisco County (415) 514-7288
ROBERT CHRISTIAN WENZ
Nurse Anesthetist, Certified Registered
505 PARNASSUS AVE
SAN FRANCISCO, CA 94143
San Francisco County (415) 353-8054

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 Gregory Zahner's NPI number?

The NPI number for Gregory Zahner is 1427685767. It was assigned to this individual provider in the NPPES registry on March 26, 2020.

Where is Gregory Zahner located?

Gregory Zahner practices at 505 Parnassus Ave, San Francisco, CA 94143. The listed phone number is (415) 476-1000.

What is Gregory Zahner's specialty?

The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.

Is Gregory Zahner enrolled in Medicare?

Yes. Gregory Zahner 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.

When was this NPI record last updated?

The NPPES record for Gregory Zahner was last updated on August 8, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 12 months 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.