John F. Simmons, MD
Hematology & Oncology Physician · Walnut Creek, CA
John F. Simmons, MD is a hematology & oncology physician with a practice address in Walnut Creek, California, and NPI 1932287000, issued on Nov 2, 2006. Check the license (California G18699, as entered in NPPES) on the Medical Board of California; the federal record below is the public data PlainDoctor holds for this provider.
- Name
- John F. Simmons
- Credential
- MD
- Primary taxonomy
- Hematology & Oncology Physician 207RH0003X
- License number
- G18699 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
- 00G186990 CA
- Entity
- Type 1 · individual
8 nearest hematology & oncology physician records → All 1,583 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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- Derek Ailes, M.D.Emergency Medical Services (Emergency Medicine) Physician1992001804
Verify John F. Simmons in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license G18699Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
John F. Simmons among 1,583 hematology & oncology physician records in California
John F. Simmons, MD is one of 1,583 hematology & oncology physician records with a practice address in California. 83% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does not. Its NPI, issued in 2006, is newer than 8% of them.
- NPI issued2006 · 8% of these records are older, 54% newer
- In a Medicare fileNo · 83% of these records are
- In the CMS Doctors and Clinicians fileNo · 71% of these records are
- Record last updated2007 · 58% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RH0003X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Hematology & Oncology Physician providers in California
There are 1,583 hematology & oncology physician records in California. No Medicare prescribing, quality score, industry payment or hospital affiliation is published for this NPI.
All 1,583 in California → Every provider in Walnut Creek → Hematology & Oncology Physician nationwide →
The 8 hematology & oncology physician records with the nearest ZIP codes
- Aram Canin, MDWalnut Creek, CA 945961669550752
- Zuo Ming Huang, MDWalnut Creek, CA 945961255308086
- Douglas Kaufman, MDWalnut Creek, CA 945961235217712
- Alice Kengla, M.D.Walnut Creek, CA 945961669506473
- Chunnan Liu, MDWalnut Creek, CA 945961154409720
- Michael Russin, MDWalnut Creek, CA 945961063590156
- Tanvir Sattar, MDWalnut Creek, CA 945961821176314
- Lisbeth Suyehira, MDWalnut Creek, CA 945961023196110
Common questions
What is John F. Simmons, MD's NPI number?
John F. Simmons, MD's National Provider Identifier (NPI) is 1932287000, issued on Nov 2, 2006. An NPI identifies a provider in billing; it is not a license.
Where is John F. Simmons, 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 John F. Simmons, MD's license?
NPPES lists California license number G18699, 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. 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.