Robert Thomas Horvat, MD, PHD
Endocrinology, Diabetes & Metabolism Physician · Mariposa, CA
Robert Thomas Horvat, MD, PHD is an endocrinology, diabetes & metabolism physician with a practice address in Mariposa, California, and NPI 1841279668, issued on Jan 10, 2006. Check the license (California A062483, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Robert Thomas Horvat
- Credential
- MD, PHD
- Primary taxonomy
- Endocrinology, Diabetes & Metabolism Physician 207RE0101X
- License numbers
- A062483 CA
A62483 CA
Self-reported in NPPES; status is on the state search - Practice location
- 5189 Hospital RD, Mariposa, CA 95338
- Phone
- (209) 966-2154
- Enumerated
- Jan 10, 2006
- Record last updated
- May 14, 2026
- Fax
- (866) 206-1883
- Medicare enrollment
- Enrolled (PECOS I20040913000669); may accept Medicare assignment
- Entity
- Type 1 · individual
Also registered at 5189 Hospital RD
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Renee Roper, M.A., LMFTMarriage & Family Therapist1427061829
Verify Robert Thomas Horvat in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A062483Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
4% fewer Medicare Part D claims than the average endocrinology, diabetes & metabolism physician in 2024
2,531 Medicare Part D claims for 331 beneficiaries, against an average of 2,630 among the 8,223 providers of this specialty who prescribed in Part D. Brand-name drugs were 37% of claims.
Most prescribed
- Levothyroxine Sodium355 claims
- Metformin Hcl235 claims
- Alendronate Sodium205 claims
- Rosuvastatin Calcium205 claims
- Atorvastatin Calcium191 claims
- Trulicity174 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 affiliation
- John C Fremont Healthcare DistrictMariposa, CA · Critical Access Hospitals
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through); hospitals matched to CMS Hospital General Information (Care Compare) (data.cms.gov).
Endocrinology, Diabetes & Metabolism Physician providers in California
There are 1,131 endocrinology, diabetes & metabolism physician records in California.
Other endocrinology, diabetes & metabolism physician records in California
- Evan Abel, MDSanta Monica, CA1619067238
- Anita Abraham, M.D.Stockton, CA1558380337
- Sallie Adams, M.D.Roseville, CA1255342085
- Helen Adelberg, M.D.Encino, CA1093935447
- Yewande Adepoju, DOOroville, CA1467892984
- David Aftergood, MDBeverly Hills, CA1639259328
- Nidhi Agarwal, MDTorrance, CA1518387125
- Bahar Aghighi, MDSanta Cruz, CA1770562134
- Tyler Aguinaldo, MDBurlingame, CA1306811906
- Susan Ahern, D.O.Ventura, CA1508156597
Common questions
What is Robert Thomas Horvat, MD, PHD's NPI number?
Robert Thomas Horvat, MD, PHD's National Provider Identifier (NPI) is 1841279668, issued on Jan 10, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Robert Thomas Horvat, MD, PHD located?
The NPPES record lists a practice address at 5189 Hospital RD, Mariposa, CA, 95338. Phone: (209) 966-2154. Providers update this record themselves, so call before visiting.
How can I verify Robert Thomas Horvat, MD, PHD's license?
NPPES lists California license number A062483, 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 Thomas Horvat, MD, PHD prescribe under Medicare Part D?
In 2024, Robert Thomas Horvat, MD, PHD had 2,531 Medicare Part D claims for 331 beneficiaries; the average among endocrinology, diabetes & metabolism physician prescribers was 2,630. 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.