Frederick Karl Gregorius, MD
Specialist · Stockton, CA
Frederick Karl Gregorius, MD is a specialist with a practice address in Stockton, California, and NPI 1013936608, issued on Jul 18, 2006. Check the license (California G15246, as entered in NPPES) with the California board that licenses this profession; the Medicare figures below come from public CMS files.
- Name
- Frederick Karl Gregorius
- Credential
- MD
- Primary taxonomy
- Specialist 174400000X
- License number
- G15246 CA
Self-reported in NPPES; status is on the state search - Practice location
- 2209 N California St, Stockton, CA 95204
- Phone
- (209) 943-0305
- Enumerated
- Jul 18, 2006
- Record last updated
- Jun 18, 2010 (not updated in 16 years: call before relying on the address or phone)
- Fax
- (209) 943-0210
- Entity
- Type 1 · individual
8 nearest specialist records → All 5,749 in California → Look up another NPI →
Also registered at 2209 N California St
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Moris Senegor, MDSpecialist1487689030
Verify Frederick Karl Gregorius in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersWhich California board licenses this profession
Search for license G15246Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
99% fewer Medicare Part D claims than the average specialist in 2024
12 Medicare Part D claims, against an average of 1,380 among the 8,233 providers of this specialty who prescribed in Part D. Brand-name drugs were 0% of 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.
Frederick Karl Gregorius among 5,749 specialist records in California
Frederick Karl Gregorius, MD is one of 5,749 specialist records with a practice address in California. 30% 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 7% of them.
- NPI issued2006 · 7% of these records are older, 60% newer
- In a Medicare fileYes · 30% of these records are
- In the CMS Doctors and Clinicians fileNo · 19% of these records are
- Record last updated2010 · 77% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 174400000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Specialist providers in California
There are 5,749 specialist records in California.
All 5,749 in California → Every provider in Stockton → Specialist nationwide →
The 8 specialist records with the nearest ZIP codes
- Vijaya Bansal, M.D.Stockton, CA 952041174665756
- Stephanie Dentoni, M.D.Stockton, CA 952041821099888
- Prasad Dighe, MDStockton, CA 952041356377071
- Ronald Dugger, MDStockton, CA 952041790720688
- Peter Gannon, MDStockton, CA 952041275560286
- Lynette Hart, MDStockton, CA 952041639154438
- Patricia Hatton, M.D.Stockton, CA 952041588778054
- Dean Karnaze, MDStockton, CA 952041346276359
Common questions
What is Frederick Karl Gregorius, MD's NPI number?
Frederick Karl Gregorius, MD's National Provider Identifier (NPI) is 1013936608, issued on Jul 18, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Frederick Karl Gregorius, MD located?
The NPPES record lists a practice address at 2209 N California St, Stockton, CA, 95204. Phone: (209) 943-0305. Providers update this record themselves, so call before visiting.
How can I verify Frederick Karl Gregorius, MD's license?
NPPES lists California license number G15246, as entered by the provider. Search the California board that licenses this profession; the NPPES record confirms identity only.
How much does Frederick Karl Gregorius, MD prescribe under Medicare Part D?
In 2024, Frederick Karl Gregorius, MD had 12 Medicare Part D claims; the average among specialist prescribers was 1,380. Part D covers Medicare prescriptions only.
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.