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DR. PETER JAMES MAZOLEWSKI M.D.
NPI 1710076773
Surgery in Walnut Creek, CA

Active since October 11, 2006PECOS EnrolledAccepts Medicare Assignment
365 LENNON LN STE 290, WALNUT CREEK, CA 94598(925) 658-5076(925) 658-5089 Get Directions Write a Review

NPPES record last updated: February 26, 2025. Verified against the NPPES registry weekly; last sync: August 02, 2026.

Record update history: Feb 26, 2025, Feb 22, 2021 (2 updates tracked since 2021).

About Dr. Peter James Mazolewski M.d. NPPES

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

DR. PETER JAMES MAZOLEWSKI M.D. (NPI 1710076773) is an individual surgery provider in Walnut Creek, California, licensed in California (A84094) and active in the NPI registry since October 2006. He is enrolled in Medicare PECOS and is a graduate of University Of Southern California Keck School Of Medicine (1994).

NPPES Registry Identity

NPI1710076773
Entity TypeIndividualMale
Primary Taxonomy208600000X
Provider Legal NameDR. PETER JAMES MAZOLEWSKICredential: M.D.
Location Address365 LENNON LN STE 290Walnut Creek, CA 94598-5915
Mailing Address365 Lennon Ln Ste 290Walnut Creek, CA 94598-5915
Phone(925) 658-5076
Fax(925) 658-5089
Sole ProprietorNo
Medical School CMSUniversity Of Southern California Keck School Of MedicineGraduated 1994
Enumeration DateOctober 11, 2006
Last NPPES UpdateFebruary 26, 20252 updates tracked since enumeration
NPPES CertifiedFebruary 26, 2025
✔ NPI 1710076773 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtySurgeryAllopathic & Osteopathic Physicians
Taxonomy Code208600000X
License✔ Licensed in CA · A84094
Definition
A general surgeon has expertise related to the diagnosis - preoperative, operative and postoperative management - and management of complications of surgical conditions in the following areas: alimentary tract; abdomen; breast, skin and soft tissue; endocrine system; head and neck surgery; pediatric surgery; surgical critical care; surgical oncology; trauma and burns; and vascular surgery. General surgeons increasingly provide care through the use of minimally invasive and endoscopic techniques. Many general surgeons also possess expertise in transplantation surgery, plastic surgery and cardiothoracic surgery.
Also ListedSpecialistTaxonomy 174400000X · License A84094 (CA)
365 LENNON LN STE 290, Walnut Creek, CA 94598
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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. Peter James Mazolewski 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 ID1951300425
PECOS Enrollment IDI20071013000072
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 5

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.
128 services69 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.
71 services70 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.
17 services14 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.
16 services16 patients
Removal of gallbladder using an endoscope 47562
This procedure, known as endoscopic gallbladder removal, involves a surgeon using a special tool called an endoscope to remove your gallbladder through small incisions. It's typically done to treat gallstones and related complications. It's a less invasive method, often leading to quicker recovery.
13 services13 patients

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 94598 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
$104.51 typical visit price
range $69.00 – $202.35
Typical copayment $26.12 (range $17.25 – $50.58)
Most-billed visit code 99203
Established Patient
$84.91 typical visit price
range $23.44 – $166.46
Typical copayment $21.22 (range $5.86 – $41.61)
Most-billed visit code 99213
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 2

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

DR. NEGAR MONAVAR SALEHOMOUM M.D.
Surgery
365 LENNON LN STE 290
WALNUT CREEK, CA 94598
Contra Costa County (925) 274-9000
DR. POORNIMA VANGURI MD
Colon & Rectal Surgery
365 LENNON LN STE 290
WALNUT CREEK, CA 94598
Contra Costa County (925) 274-9000

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 Peter Mazolewski's NPI number?

The NPI number for Peter Mazolewski is 1710076773. It was assigned to this individual provider in the NPPES registry on October 11, 2006.

Where is Peter Mazolewski located?

Peter Mazolewski practices at 365 Lennon Ln Ste 290, Walnut Creek, CA 94598. The listed phone number is (925) 658-5076.

What is Peter Mazolewski's specialty?

The primary specialty registered for this NPI is Surgery with taxonomy code 208600000X.

Is Peter Mazolewski enrolled in Medicare?

Yes. Peter Mazolewski 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 Peter Mazolewski was last updated on February 26, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 17 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.