Katy Kai-Ju Tsai, MD
Internal Medicine Physician · San Francisco, CA
Katy Kai-Ju Tsai, MD is an internal medicine physician with a practice address in San Francisco, California, and NPI 1417275827, issued on May 10, 2010. Check the license (California A124908, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Katy Kai-Ju Tsai
- Credential
- MD
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- A124908 CA
Self-reported in NPPES; status is on the state search - Practice location
- 1600 Divisadero St, San Francisco, CA 94143
- Phone
- (415) 353-9900
- Enumerated
- May 10, 2010
- Record last updated
- Aug 10, 2018 (not updated in 8 years: call before relying on the address or phone)
- Medicare enrollment
- Enrolled (PECOS I20150715002480); accepts Medicare assignment
- Medical or professional school
- Warren Alpert Medical School Of Brown University, 2010
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 17,696 in California → Look up another NPI →
Also registered at 1600 Divisadero St
A shared address usually means a shared clinic or building; it does not show who employs whom.
- David AlfonRegistered Nurse1558106336
- Christian Apfel, MD, PHDAnesthesiology Physician1578651105
- Fady BekheetPharmacist1780223131
- Fletcher Bell, MDInternal Medicine Physician1811647514
- Lauren Boreta, M.D.Radiation Oncology Physician1679990071
- Ronald Braun, M.D.Anesthesiology Physician1700865367
Verify Katy Kai-Ju Tsai in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A124908Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
98% fewer Medicare Part D claims than the average internal medicine physician in 2024
69 Medicare Part D claims for 25 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 38% of claims.
Most prescribed
- Prednisone11 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.
The practice group's MIPS final score for 2023 (Medicare payment program): 74.5 of 100
The Merit-based Incentive Payment System score is reported for the practice group, not for one clinician alone. Four categories are weighted into the final score; the average among 454,083 clinicians with a measured score was 83.5.
Source: CMS Quality Payment Program, MIPS performance year 2023, group reporting; category weights for 2023 (qpp.cms.gov).
Industry payments in 2024: $2,609.21
4 payments; by number, the most common kind was food and beverage; the largest payer was E.R. Squibb & Sons, L.L.C. The 50,334 providers of this specialty with any payment received $1,303.06 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.
Bills Medicare through 2 group practices
- Ucsf Medical Group Business ServicesSan Francisco, CA
- University OF California San FranciscoSan Francisco, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Katy Kai-Ju Tsai among 17,696 internal medicine physician records in California
Katy Kai-Ju Tsai, MD 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 2010, is newer than 63% of them.
- NPI issued2010 · 63% of these records are older, 34% newer
- In a Medicare fileYes · 79% of these records are
- In the CMS Doctors and Clinicians fileYes · 63% of these records are
- Graduated2010 · median 2004 among the 11,065 with a school on file
- Record last updated2018 · 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).
1,318 internal medicine physician records list a practice address in San Francisco
They are 1,318 of the 38,143 NPPES records with a practice address in San Francisco, and 17,696 internal medicine physician records in California.
All 17,696 in California → Every provider in San Francisco → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Nathan Bass, MDSan Francisco, CA 941431689638959
- Margaret Fang, MDSan Francisco, CA 941431417911462
- Katherine Julian, MDSan Francisco, CA 941431003879826
- John Kane, MDSan Francisco, CA 941431467416461
- Suneil Koliwad, M.D., PH.D.San Francisco, CA 941431225006687
- Bernard Lo, MDSan Francisco, CA 941431184688137
- Stephen McPhee, MDSan Francisco, CA 941431124082490
- Andrew Posselt, MDSan Francisco, CA 941431235193616
Common questions
What is Katy Kai-Ju Tsai, MD's NPI number?
Katy Kai-Ju Tsai, MD's National Provider Identifier (NPI) is 1417275827, issued on May 10, 2010. An NPI identifies a provider in billing; it is not a license.
Where is Katy Kai-Ju Tsai, MD located?
The NPPES record lists a practice address at 1600 Divisadero St, San Francisco, CA, 94143. Phone: (415) 353-9900. Providers update this record themselves, so call before visiting.
How can I verify Katy Kai-Ju Tsai, MD's license?
NPPES lists California license number A124908, 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 Katy Kai-Ju Tsai, MD prescribe under Medicare Part D?
In 2024, Katy Kai-Ju Tsai, MD had 69 Medicare Part D claims for 25 beneficiaries; the average among internal medicine physician prescribers was 3,176. Part D covers Medicare prescriptions only.
What is Katy Kai-Ju Tsai, MD's MIPS final score?
The 2023 MIPS final score is 74.5 of 100, reported for the practice group. The average among 454,083 clinicians with a measured score was 83.5.
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.