Ivor Royston, M.D.
Specialist · San Diego, CA
Ivor Royston, M.D. is a specialist with a practice address in San Diego, California, and NPI 1174880074, issued on Apr 16, 2012. Check the license (California G20974, as entered in NPPES) with the California board that licenses this profession; the Medicare figures below come from public CMS files.
- Name
- Ivor Royston
- Credential
- M.D.
- Primary taxonomy
- Specialist 174400000X
- License number
- G20974 CA
Self-reported in NPPES; status is on the state search - Practice location
- 9393 Towne Centre Dr, San Diego, CA 92121
- Phone
- (858) 964-5004
- Enumerated
- Apr 16, 2012
- Record last updated
- Apr 16, 2012 (not updated in 14 years: call before relying on the address or phone)
- Fax
- (858) 362-1051
- Entity
- Type 1 · individual
8 nearest specialist records → All 5,749 in California → Look up another NPI →
Also registered at 9393 Towne Centre Dr
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Isan Chen, M.D.Hematology & Oncology Physician1407142409
Verify Ivor Royston in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersWhich California board licenses this profession
Search for license G20974Check 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
19 Medicare Part D claims, against an average of 1,380 among the 8,233 providers of this specialty who prescribed in Part D.
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.
Ivor Royston among 5,749 specialist records in California
Ivor Royston, M.D. 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 2012, is newer than 66% of them.
- NPI issued2012 · 66% of these records are older, 31% newer
- In a Medicare fileYes · 30% of these records are
- In the CMS Doctors and Clinicians fileNo · 19% of these records are
- Record last updated2012 · 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 San Diego → Specialist nationwide →
The 8 specialist records with the nearest ZIP codes
- William Bailey, D.O.San Diego, CA 921211063623486
- Chase Bennett, DDSSan Diego, CA 921211043566706
- David Bortz, M.D., F.A.C.P.San Diego, CA 921211336291665
- Mindy Cetel, M.D.San Diego, CA 921211003843335
- Lyndon Chang, MDSan Diego, CA 921211275593261
- Russell Dunnum, M.D.San Diego, CA 921211396856290
- Milton Erman, M.D.San Diego, CA 921211619993490
- Michael Maio, C.E.S.,C.P.T.,C.N.San Diego, CA 921211396076998
Common questions
What is Ivor Royston, M.D.'s NPI number?
Ivor Royston, M.D.'s National Provider Identifier (NPI) is 1174880074, issued on Apr 16, 2012. An NPI identifies a provider in billing; it is not a license.
Where is Ivor Royston, M.D. located?
The NPPES record lists a practice address at 9393 Towne Centre Dr, San Diego, CA, 92121. Phone: (858) 964-5004. Providers update this record themselves, so call before visiting.
How can I verify Ivor Royston, M.D.'s license?
NPPES lists California license number G20974, as entered by the provider. Search the California board that licenses this profession; the NPPES record confirms identity only.
How much does Ivor Royston, M.D. prescribe under Medicare Part D?
In 2024, Ivor Royston, M.D. had 19 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.