Gregory Chen, M.D.
Urology Physician · Hayward, CA
Gregory Chen, M.D. is a urology physician with a practice address in Hayward, California, and NPI 1699853457, issued on Nov 1, 2006. Check the license (California G84622, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Gregory Chen
- Credential
- M.D.
- Primary taxonomy
- Urology Physician 208800000X
- License number
- G84622 CA
Self-reported in NPPES; status is on the state search - Practice location
- 27303 Sleepy Hollow Ave S, Hayward, CA 94545
- Phone
- (510) 454-1000
- Enumerated
- Nov 1, 2006
- Entity
- Type 1 · individual
Also registered at 27303 Sleepy Hollow Ave S
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Malini Amin, MDPediatrics Physician1801095252
- Madhulika Battu, MDStudent in an Organized Health Care Education/Training Program1245736370
- Mario Bernaba, MDInternal Medicine Physician1205499506
- Neelam Bhalla, M.D.Nephrology Physician1639118052
- Pooja Bhoopalam, PHARMDPharmacist1871022186
- Natalie CacAllergy & Immunology Physician1205006657
Verify Gregory Chen in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license G84622Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS, AOA, NCCPA, AANPNot checked
43% more Medicare Part D claims than the average urology physician in 2024
1,939 Medicare Part D claims for 742 beneficiaries, against an average of 1,354 among the 9,936 providers of this specialty who prescribed in Part D. Brand-name drugs were 4% of claims. 43 claims were for opioids.
Most prescribed
- Tamsulosin Hcl530 claims
- Finasteride426 claims
- Trospium Chloride195 claims
- Terazosin Hcl162 claims
- Cefadroxil90 claims
- Myrbetriq69 claims
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
One hospital or facility affiliation
- Permanente Medical Group IncHayward, CA
Source: CMS Doctors and Clinicians affiliations; Hospital General Information (Care Compare) (data.cms.gov). Star ratings are CMS hospital ratings, not ratings of this provider.
Urology Physician providers in California
There are 1,421 urology physician records in California.
Other urology physician records in California
- David Aaronson, MDOakland, CA1215053129
- Jason Abber, MDPanorama City, CA1356366926
- Marc Abboud, MDLos Alamitos, CA1265096531
- George AbdelsayedAnaheim, CA1568721843
- Garen AbediDowney, CA1285909051
- Jennifer Abidari, MDStanford, CA1811098197
- Sherif Aboseif, MDOxnard, CA1093882995
- Parwiz Abrahimi, M.D., PH.D.Los Angeles, CA1154857613
- Anthony Acquaviva, MDVallejo, CA1457439283
- Theodore Affue, M.D.El Centro, CA1386674000
Common questions
What is Gregory Chen, M.D.'s NPI number?
Gregory Chen, M.D.'s National Provider Identifier (NPI) is 1699853457, issued on Nov 1, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Gregory Chen, M.D. located?
The NPPES record lists a practice address at 27303 Sleepy Hollow Ave S, Hayward, CA, 94545. Phone: (510) 454-1000. Providers update this record themselves, so call before visiting.
How can I verify Gregory Chen, M.D.'s license?
NPPES lists California license number G84622, 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.
How much does Gregory Chen, M.D. prescribe under Medicare Part D?
In 2024, Gregory Chen, M.D. had 1,939 Medicare Part D claims for 742 beneficiaries; the average among urology physician prescribers was 1,354. Part D covers Medicare prescriptions only.
Source: CMS National Plan and Provider Enumeration System (NPPES), loaded Aug 27, 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.
Every figure on PlainDoctor is rendered directly from the federal CMS NPPES registry, Medicare Part D, MIPS, and Open Payments records, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 27, 2026.