Alexander Louis Kostrinsky-Thomas, DO
Hospitalist Physician · San Francisco, CA
Alexander Louis Kostrinsky-Thomas, DO is a hospitalist physician with a practice address in San Francisco, California, and NPI 1700528833, issued on Apr 9, 2022. Check the license (California 20A21736, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Alexander Louis Kostrinsky-Thomas
- Credential
- DO
- Primary taxonomy
- Hospitalist Physician 208M00000X
- License number
- 20A21736 CA
Self-reported in NPPES; status is on the state search - Practice location
- 10 Koret Way, San Francisco, CA 94143
- Phone
- (415) 514-1378
- Enumerated
- Apr 9, 2022
- Record last updated
- Jun 7, 2025
- Medicare enrollment
- Enrolled (PECOS I20251105003278); accepts Medicare assignment
- Entity
- Type 1 · individual
8 nearest hospitalist physician records → All 3,099 in California → Look up another NPI →
Also registered at 10 Koret Way
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Frank Brodie, MDOphthalmology Physician1811317357
- Joseph Crawford, MDOphthalmology Physician1831141712
- Michael Seider, M.D.Ophthalmology Physician1427286046
- Diamond Tam, MDOphthalmology Physician1023235124
Verify Alexander Louis Kostrinsky-Thomas in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license 20A21736Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
77% fewer Medicare Part D claims than the average hospitalist physician in 2024
119 Medicare Part D claims for 22 beneficiaries, against an average of 521 among the 21,613 providers of this specialty who prescribed in Part D.
Most prescribed
- Atorvastatin Calcium19 claims
- Montelukast Sodium13 claims
- Fenofibrate12 claims
- Baclofen11 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.
Bills Medicare through one group practice
- Regents OF The University OF CaliforniaSan Francisco, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Alexander Louis Kostrinsky-Thomas among 3,099 hospitalist physician records in California
Alexander Louis Kostrinsky-Thomas, DO is one of 3,099 hospitalist physician records with a practice address in California. 90% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2022, is newer than 94% of them.
- NPI issued2022 · 94% of these records are older, 2% newer
- In a Medicare fileYes · 90% of these records are
- In the CMS Doctors and Clinicians fileYes · 81% of these records are
- Graduated2022 · median 2010 among the 2,505 with a school on file
- Record last updated2025 · 49% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 208M00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Hospitalist Physician providers in California
There are 3,099 hospitalist physician records in California.
All 3,099 in California → Every provider in San Francisco → Hospitalist Physician nationwide →
The 8 hospitalist physician records with the nearest ZIP codes
- Seth Blumberg, MD PHDSan Francisco, CA 941431255595443
- Robertino Garcia Cortes, MDSan Francisco, CA 941431770872590
- Robin Goldman, MD, MPHSan Francisco, CA 941431033439906
- Win Han, MDSan Francisco, CA 941431619110384
- Ari HoffmanSan Francisco, CA 941431346566221
- Alison Kuchta, M.D.San Francisco, CA 941431063704963
- Andrew Lai, M.D.San Francisco, CA 941431861666281
- Khoa Lam, M.D.San Francisco, CA 941431801114095
Common questions
What is Alexander Louis Kostrinsky-Thomas, DO's NPI number?
Alexander Louis Kostrinsky-Thomas, DO's National Provider Identifier (NPI) is 1700528833, issued on Apr 9, 2022. An NPI identifies a provider in billing; it is not a license.
Where is Alexander Louis Kostrinsky-Thomas, DO located?
The NPPES record lists a practice address at 10 Koret Way, San Francisco, CA, 94143. Phone: (415) 514-1378. Providers update this record themselves, so call before visiting.
How can I verify Alexander Louis Kostrinsky-Thomas, DO's license?
NPPES lists California license number 20A21736, 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 Alexander Louis Kostrinsky-Thomas, DO prescribe under Medicare Part D?
In 2024, Alexander Louis Kostrinsky-Thomas, DO had 119 Medicare Part D claims for 22 beneficiaries; the average among hospitalist physician prescribers was 521. 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.