Gregory A. Marshall, MD
Urology Physician · Walnut Creek, CA
Gregory A. Marshall, MD is a urology physician with a practice address in Walnut Creek, California, and NPI 1437237526, issued on Nov 2, 2006. Check the license (California G65068, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Gregory A. Marshall
- Credential
- MD
- Primary taxonomy
- Urology Physician 208800000X
- License number
- G65068 CA
Self-reported in NPPES; status is on the state search - Practice location
- 1425 S Main St, Walnut Creek, CA 94596
- Phone
- (925) 295-4000
- Enumerated
- Nov 2, 2006
- Record last updated
- Jul 8, 2007 (not updated in 19 years: call before relying on the address or phone)
- Medicaid ID
- 00G650680 CA
- Entity
- Type 1 · individual
8 nearest urology physician records → All 1,524 in California → Look up another NPI →
Also registered at 1425 S Main St
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Peter Ackerman, MDEmergency Medicine Physician1427435023
- Aaron Mark Acosta, DOEmergency Medicine Physician1538789987
- Basil Adad, MDOtolaryngology Physician1487732574
- Derek Ailes, M.D.Emergency Medical Services (Emergency Medicine) Physician1992001804
Verify Gregory A. Marshall in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license G65068Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
Industry payments in 2024: $40.52
2 payments; by number, the most common kind was food and beverage; the largest payer was Medline Industries LP. The 9,340 providers of this specialty with any payment received $3,800.04 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.
Gregory A. Marshall among 1,524 urology physician records in California
Gregory A. Marshall, MD is one of 1,524 urology physician records with a practice address in California. 82% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2006, is newer than 8% of them.
- NPI issued2006 · 8% of these records are older, 51% newer
- In a Medicare fileYes · 82% of these records are
- In the CMS Doctors and Clinicians fileNo · 69% of these records are
- Record last updated2007 · 59% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 208800000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Urology Physician providers in California
There are 1,524 urology physician records in California.
All 1,524 in California → Every provider in Walnut Creek → Urology Physician nationwide →
The 8 urology physician records with the nearest ZIP codes
- Amir Arsanjani, MDWalnut Creek, CA 945961154486793
- Andrew Chen, M.D.Walnut Creek, CA 945961811039480
- Michael Choi, MDWalnut Creek, CA 945961215015797
- Jason Frankel, MDWalnut Creek, CA 945961750729976
- Scot Hagey, MDWalnut Creek, CA 945961215015896
- John Oh, MDWalnut Creek, CA 945961649358730
- Raymond Rosenbaum, MDWalnut Creek, CA 945961679651749
- Malcolm Scott, MDWalnut Creek, CA 945961750469854
Common questions
What is Gregory A. Marshall, MD's NPI number?
Gregory A. Marshall, MD's National Provider Identifier (NPI) is 1437237526, issued on Nov 2, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Gregory A. Marshall, MD located?
The NPPES record lists a practice address at 1425 S Main St, Walnut Creek, CA, 94596. Phone: (925) 295-4000. Providers update this record themselves, so call before visiting.
How can I verify Gregory A. Marshall, MD's license?
NPPES lists California license number G65068, as entered by the provider. Search the Medical Board of California at https://www.mbc.ca.gov/License-Verification/default.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.