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

Dr. John Stephen Hammes, MD

Individual provider Nephrology Physician · NPI 1891766994

Dr. John Stephen Hammes, MD practises Nephrology in San Diego, California. Graduated from Uniformed Services Uhs Fe Hebert School of Med in 1993, 33 years ago. Practices with Emergency and Acute Care Medical Corporation, a 439-clinician group, accepts Medicare assignment and offers telehealth. Licensed in California.

Years since qualifying
33
Trained at
Uniformed Services Uhs Fe Hebert School of Med
Licensed in
CA
In the registry since
2006
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

8885 Rio San Diego Dr Ste 212
San Diego, CA 92108-1626
Phone: (619) 299-2350
Fax: (619) 297-8379
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Nephrology Physician (primary) Taxonomy 207RN0300X · Licence G84351 (CA)

Record details

NPI number1891766994
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedJanuary 28, 2006
Last updated in NPPESJune 15, 2026
Certification dateJune 15, 2026

Medicare enrollment

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

Medicare specialtyNEPHROLOGY
Also practisesINTERNAL MEDICINE
Medical schoolUNIFORMED SERVICES UHS FE HEBERT SCHOOL OF MED
Graduated 1993 (33 years in practice)
Group practice Emergency And Acute Care Medical Corporation — 439 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
TelehealthOffers telehealth services
Practice locations3 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 patients432
Services billed 2,351 a service is one billed item, such as a visit, a test or a procedure
Average patient age72

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.

Practises at

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

Colleagues at Emergency and Acute Care Medical Corporation

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 439 clinicians in the practice; 12 are shown here.

Other providers in San Diego