Robert Charles Southmayd, D.O.
Internal Medicine Physician · Ceres, CA
Robert Charles Southmayd, D.O. is an internal medicine physician with a practice address in Ceres, California, and NPI 1982700969, issued on Sep 16, 2006. Check the license (California 5298, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Robert Charles Southmayd
- Credential
- D.O.
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License numbers
- 5298 CA
20A5298 CA
Self-reported in NPPES; status is on the state search - Practice location
- 1768 Mitchell RD Ste 301, Ceres, CA 95307
- Phone
- (209) 353-4838
- Enumerated
- Sep 16, 2006
- Record last updated
- Oct 22, 2025
- Medicaid ID
- 00AX52980 CA
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 17,696 in California → Look up another NPI →
Also registered at 1768 Mitchell RD Ste 301
A shared address usually means a shared clinic or building; it does not show who employs whom.
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Verify Robert Charles Southmayd in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license 5298Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
79% fewer Medicare Part D claims than the average internal medicine physician in 2024
681 Medicare Part D claims for 370 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. 12 claims were for opioids.
Most prescribed
- Azithromycin92 claims
- Sulfamethoxazole-Trimethoprim58 claims
- Ibuprofen28 claims
- Nitrofurantoin Mono-Macro26 claims
- Paxlovid25 claims
- Promethazine-Dm24 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.
Robert Charles Southmayd among 17,696 internal medicine physician records in California
Robert Charles Southmayd, D.O. is one of 17,696 internal medicine physician records with a practice address in California. 79% 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 5% of them.
- NPI issued2006 · 5% of these records are older, 56% newer
- In a Medicare fileYes · 79% of these records are
- In the CMS Doctors and Clinicians fileNo · 63% of these records are
- Record last updated2025 · 61% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207R00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Internal Medicine Physician providers in California
There are 17,696 internal medicine physician records in California.
All 17,696 in California → Every provider in Ceres → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Adrian Carreon, M.D.Atwater, CA 953011679598536
- Soma Krishnamoorthi, M.D.Escalon, CA 953201013011055
- Katherine Newcomb, M.D.Groveland, CA 953211528193786
- Marissa Wen, MDLathrop, CA 953301467999169
- Maria Bacay, MDManteca, CA 953361679599070
- Bernard Bacay, MDManteca, CA 953361629094032
- Santokh Bhullar, MDManteca, CA 953361760594105
- Russell Carter, MDManteca, CA 953361528049988
Common questions
What is Robert Charles Southmayd, D.O.'s NPI number?
Robert Charles Southmayd, D.O.'s National Provider Identifier (NPI) is 1982700969, issued on Sep 16, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Robert Charles Southmayd, D.O. located?
The NPPES record lists a practice address at 1768 Mitchell RD Ste 301, Ceres, CA, 95307. Phone: (209) 353-4838. Providers update this record themselves, so call before visiting.
How can I verify Robert Charles Southmayd, D.O.'s license?
NPPES lists California license number 5298, 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 Robert Charles Southmayd, D.O. prescribe under Medicare Part D?
In 2024, Robert Charles Southmayd, D.O. had 681 Medicare Part D claims for 370 beneficiaries; the average among internal medicine physician prescribers was 3,176. 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.