ALEXANDER LOUIS KOSTRINSKY-THOMAS DO
NPI 1700528833
Hospitalist in San Francisco, CA
About Alexander Louis Kostrinsky-thomas Do NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
ALEXANDER LOUIS KOSTRINSKY-THOMAS DO (NPI 1700528833) is an individual hospitalist provider in San Francisco, California, licensed in California (20A21736) and active in the NPI registry since April 2022. He is enrolled in Medicare PECOS, maintains a secondary practice location in San Jose, and is a graduate of Other (2022).
NPPES Registry Identity
Specialties & Licenses 2
Secondary Practice Location 1
Medicare Participation & PECOS CMS
Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.
Medicare Enrollment Status
Enrolled in Medicare and accepts Medicare assignment
Alexander Louis Kostrinsky-thomas Do is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.
Medicare Billing Reassignments
3Medicare enrollment records show Alexander Kostrinsky-thomas reassigns Medicare billing to 3 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
San Francisco, CA 94143
- Reassigned Medicare billing, California enrollment
- 2,112 clinicians in this Medicare group
San Francisco, CA 94122
- Reassigned Medicare billing, California enrollment
- 5,544 clinicians in this Medicare group
San Francisco, CA 94143
- Reassigned Medicare billing, California enrollment
- 5,645 clinicians in this Medicare group
Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.
Physician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 94143 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
Other Providers at the Same Location NPPES 4
Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.
Frequently Asked Questions NPPES & CMS
Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.
What is Alexander Kostrinsky-thomas's NPI number?
The NPI number for Alexander Kostrinsky-thomas is 1700528833. It was assigned to this individual provider in the NPPES registry on April 9, 2022.
Where is Alexander Kostrinsky-thomas located?
Alexander Kostrinsky-thomas practices at 10 Koret Way, San Francisco, CA 94143. The listed phone number is (415) 514-1378.
What is Alexander Kostrinsky-thomas's specialty?
The primary specialty registered for this NPI is Hospitalist with taxonomy code 208M00000X.
Is Alexander Kostrinsky-thomas enrolled in Medicare?
Yes. Alexander Kostrinsky-thomas is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.
Which organizations bill Medicare for Alexander Kostrinsky-thomas's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Alexander Kostrinsky-thomas reassigns Medicare benefits to 3 organizations: Regents Of The University Of California (San Francisco, CA), Ucsf Medical Group Business Services (San Francisco, CA) and University Of California San Francisco (San Francisco, CA). Each reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for Alexander Kostrinsky-thomas's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
When was this NPI record last updated?
The NPPES record for Alexander Kostrinsky-thomas was last updated on June 7, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 16 months ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.
# Alexander Louis Kostrinsky-Thomas, DO · NPI 1700528833
Hospitalist physician in San Francisco, California. Individual provider, active in the CMS NPPES registry since April 9, 2022.
## Identity
- **NPI:** 1700528833 (Entity type: Individual)
- **Enumerated:** April 9, 2022
- **Primary specialty:** Hospitalist · taxonomy 208M00000X
- **State license:** 20A21736 (California)
- **Sole proprietor:** No
## Practice location
- **Address:** 10 KORET WAY, San Francisco, CA 94143-2218
- **Phone:** (415) 514-1378
## Medicare
- **Medicare:** Enrolled (PECOS); accepts Medicare assignment
- **Ordering & referring:** eligible for Part B labs & imaging, durable medical equipment, home health, power mobility devices
- **Bills Medicare through:** 3 organizations under Medicare reassignment (form CMS-855R): Regents Of The University Of California (NPI 1376613943, San Francisco, CA); Ucsf Medical Group Business Services (NPI 1477624104, San Francisco, CA); University Of California San Francisco (NPI 1164512851, San Francisco, CA) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Other, class of 2022
## Record status
- **NPPES last updated:** June 7, 2025
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Source: [NPI Profile](https://npiprofile.com/npi/1700528833) · Data from the CMS NPPES public registry.