Recently Updated NPI Information — some details in this NPI profile have been updated in the NPI registry within the last 60 days.

DR. JOHN STEPHEN HAMMES M.D.
NPI 1891766994
Internal Medicine - Nephrology in San Diego, CA

Q: What is John Hammes's NPI number?

The NPI number for John Hammes is 1891766994. It was assigned to this individual provider in the NPPES registry on January 28, 2006.

Q: What is John Hammes's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Nephrology, with taxonomy code 207RN0300X.

Q: When was this NPI record last updated?

The NPPES record for John Hammes was last updated on June 15, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 58 days 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.

Active since January 28, 2006PECOS EnrolledAccepts Medicare Assignment

8885 RIO SAN DIEGO DR STE 212, SAN DIEGO, CA 92108(619) 299-2350(619) 297-8379 Get Directions Write a Review

NPPES record last updated: June 15, 2026. Verified against the NPPES registry weekly; last sync: August 09, 2026.

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About Dr. John Stephen Hammes M.d. NPPES

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

DR. JOHN STEPHEN HAMMES M.D. (NPI 1891766994) is an individual nephrology provider in San Diego, California, licensed in California (G84351) and active in the NPI registry since January 2006. He is enrolled in Medicare PECOS and is a graduate of Uniformed Services Uhs Fe Hebert School Of Med (1993).

NPPES Registry Identity

NPI1891766994

Entity TypeIndividualMale

Primary Taxonomy207RN0300X

Provider Legal NameDR. JOHN STEPHEN HAMMESCredential: M.D.

Location Address8885 RIO SAN DIEGO DR STE 212San Diego, CA 92108-1626

Mailing Address4225 Executive Sq Ste 450La Jolla, CA 92037-8411 · (858) 810-0000 · Fax (858) 268-1911

Phone(619) 299-2350

Fax(619) 297-8379

Sole ProprietorNo

Medical School CMSUniformed Services Uhs Fe Hebert School Of MedGraduated 1993

Enumeration DateJanuary 28, 2006

Last NPPES UpdateJune 15, 2026

NPPES CertifiedJune 15, 2026

✔ NPI 1891766994 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal Medicine · NephrologyAllopathic & Osteopathic Physicians

Taxonomy Code207RN0300X

License✔ Licensed in CA · G84351

Definition

An internist who treats disorders of the kidney, high blood pressure, fluid and mineral balance and dialysis of body wastes when the kidneys do not function. This specialist consults with surgeons about kidney transplantation.

8885 RIO SAN DIEGO DR STE 212, San Diego, CA 92108

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Other Identifiers 3

OtherCB204086CA · So Ca Medicare Ptan

OtherG84351CA · Ca License

OtherCA125550CA · No Ca Medicare Ptan

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. John Stephen Hammes 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 ID7012166432

PECOS Enrollment IDI20120928000492

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.

Areas of Expertise CMS Part B claims 11

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.

Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes 99232

Follow-up hospital inpatient care involves daily check-ups while you're admitted in the hospital. Typically, a healthcare provider spends about 25 minutes each day reviewing your condition, adjusting treatment if needed, and answering any questions you might have.

792 services202 patients

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.

251 services138 patients

Hemodialysis procedure with physician evaluation 90935

Hemodialysis is a treatment that uses a machine to filter waste and excess fluid from your blood when your kidneys can't. A physician checks your health before, during, and after the procedure to ensure it's working effectively for you.

238 services76 patients

Dialysis services, 4 or more physician visits per month (20 years or older) 90960

Dialysis is a treatment that filters and purifies your blood using a machine. It helps keep your fluids and electrolytes in balance when the kidneys can't do their job. This service includes 4 or more visits per month with a physician to monitor your health and adjust your treatment as needed.

235 services36 patients

Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes 99223

Initial hospital inpatient care per day, typically 70 minutes, refers to the daily medical service provided to patients admitted to the hospital. This includes a comprehensive evaluation, diagnosis, treatment plan, and monitoring of your health condition. It ensures your well-being during your hospital stay.

155 services137 patients

Dialysis procedure including 1 evaluation 90945

Dialysis is a treatment that filters and purifies the blood when your kidneys can't do their job. The procedure involves circulating your blood through a machine that removes waste products. An evaluation is done beforehand to assess your health and determine the best approach for your treatment.

110 services16 patients

Home dialysis services per month (20 years or older) 90966

Home dialysis services provide kidney treatment for patients aged 20 or older right in their own homes. This service includes necessary equipment, supplies, and support for performing dialysis. It's a convenient option that allows patients to maintain their daily routines while receiving essential care.

103 services16 patients

Dialysis services, 2-3 physician visits per month (20 years or older) 90961

Dialysis is a treatment that performs the function of healthy kidneys if they're not working properly. It removes waste and excess fluid from your blood. 2-3 physician visits per month are recommended for monitoring your health and adjusting your treatment as needed. This service is available for those aged 20 years and older.

69 services30 patients

Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes 99233

Follow-up hospital inpatient care per day typically involves a 35-minute check-up by your healthcare provider. This service includes monitoring your health progress, adjusting your treatment plan if needed, and answering any questions you may have about your condition or care.

37 services20 patients

Subsequent hospital care with straightforward or low level of medical decision making, per day, if using time, at least 25 minutes 99231

Follow-up hospital inpatient care is a daily service where a healthcare professional checks on your health progress during your hospital stay. Each session typically lasts 15 minutes, involving updates on your condition and adjustments to your treatment plan, if necessary.

25 services13 patients

New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more 99204

This is a first-time office or outpatient visit lasting between 45-59 minutes. The healthcare provider evaluates your health, discusses your medical history, and may suggest further tests or treatments. It's an opportunity to ask questions and understand your health better.

19 services19 patients

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 92108 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

$140.22 typical visit price

range $62.10 – $184.71

Typical copayment $35.05 (range $15.52 – $46.17)

Most-billed visit code 99204

Established Patient

$108.42 typical visit price

range $20.62 – $151.42

Typical copayment $27.10 (range $5.15 – $37.85)

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.

Referred Medical Equipment & Supplies CMS DME claims 5

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

Tacrolimus, immediate release, oral, 1 mg J7507

Treatment-Treatment - Miscellaneous · category RX029N

1 supplier12 claims720 services$0.32 avg. paid by Medicare

Mycophenolate mofetil, oral, 250 mg J7517

Treatment-Treatment - Miscellaneous · category RX029N

2 suppliers14 claims1,380 services$0.20 avg. paid by Medicare

Sirolimus, oral, 1 mg J7520

Treatment-Treatment - Miscellaneous · category RX029N

4 suppliers35 claims3,900 services$2.74 avg. paid by Medicare

Pharmacy supply fee for oral anti-cancer, oral anti-emetic or immunosuppressive drug(s); for the first prescription in a 30-day period Q0511

Treatment-Chemotherapy · category RH012N

5 suppliers32 claims32 services$18.92 avg. paid by Medicare

Pharmacy supply fee for oral anti-cancer, oral anti-emetic or immunosuppressive drug(s); for a subsequent prescription in a 30-day period Q0512

Treatment-Chemotherapy · category RH012N

4 suppliers35 claims35 services$12.64 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 6

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

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Internal Medicine (Nephrology)