Weiyun Z. Ai, MD
Medical Oncology Physician · San Francisco, CA
Weiyun Z. Ai, MD is a medical oncology physician with a practice address in San Francisco, California, and NPI 1649346842, issued on Nov 28, 2006. Check the license (California A78202, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Weiyun Z. Ai
- Credential
- MD
- Primary taxonomy
- Medical Oncology Physician 207RX0202X
- License number
- A78202 CA
Self-reported in NPPES; status is on the state search - Practice location
- 400 Parnassus Ave, San Francisco, CA 94143
- Phone
- (415) 353-2737
- Enumerated
- Nov 28, 2006
- Record last updated
- Jun 6, 2008 (not updated in 18 years: call before relying on the address or phone)
- Medicare enrollment
- Enrolled (PECOS I20070108000499); accepts Medicare assignment
- Medical or professional school
- Stanford University School Of Medicine, 2000
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest medical oncology physician records → All 447 in California → Look up another NPI →
Also registered at 400 Parnassus Ave
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Jessica Abele, DPTPhysical Therapist1851648133
- Ian Adatia, MB CHBPediatric Cardiology Physician1427085299
- Daniel Adelman, M.D.Internal Medicine Physician1922041821
- Joshua Adler, MDInternal Medicine Physician1194781351
- Justin Ahn, M.D.Urology Physician1063755148
- Christine Ainza, AGACNP-BCAcute Care Nurse Practitioner1346783974
Verify Weiyun Z. Ai in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A78202Check 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 medical oncology physician in 2024
673 Medicare Part D claims for 104 beneficiaries, against an average of 703 among the 4,230 providers of this specialty who prescribed in Part D. 12 claims were for opioids.
Most prescribed
- Acyclovir85 claims
- Valacyclovir38 claims
- Prednisone37 claims
- Brukinsa36 claims
- Ondansetron Hcl34 claims
- Venclexta33 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: $7,858.26
10 payments; by number, the most common kind was food and beverage; the largest payer was Acrotech Biopharma Inc. The 3,343 providers of this specialty with any payment received $11,773.47 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 3 group practices
- Regents OF The University OF CaliforniaSan Francisco, CA
- 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).
Weiyun Z. Ai among 447 medical oncology physician records in California
Weiyun Z. Ai, MD is one of 447 medical oncology physician records with a practice address in California. 82% 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 6% of them.
- NPI issued2006 · 6% of these records are older, 55% newer
- In a Medicare fileYes · 82% of these records are
- In the CMS Doctors and Clinicians fileYes · 70% of these records are
- Graduated2000 · median 2004 among the 312 with a school on file
- Record last updated2008 · 41% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RX0202X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Medical Oncology Physician providers in California
There are 447 medical oncology physician records in California.
All 447 in California → Every provider in San Francisco → Medical Oncology Physician nationwide →
The 8 medical oncology physician records with the nearest ZIP codes
- Donald Abrams, MDSan Francisco, CA 941431679530018
- Rohit Bose, M.D., PH.D.San Francisco, CA 941431710140850
- Edward Cha, M.D.San Francisco, CA 941431134330988
- Lloyd Damon, MDSan Francisco, CA 941431548224058
- Steven Deeks, MDSan Francisco, CA 941431073604666
- Kristen Hege, MDSan Francisco, CA 941431710925987
- Gerald Hsu, MDSan Francisco, CA 941431467501080
- Lawrence Kaplan, MDSan Francisco, CA 941431437113586
Common questions
What is Weiyun Z. Ai, MD's NPI number?
Weiyun Z. Ai, MD's National Provider Identifier (NPI) is 1649346842, issued on Nov 28, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Weiyun Z. Ai, MD located?
The NPPES record lists a practice address at 400 Parnassus Ave, San Francisco, CA, 94143. Phone: (415) 353-2737. Providers update this record themselves, so call before visiting.
How can I verify Weiyun Z. Ai, MD's license?
NPPES lists California license number A78202, 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 Weiyun Z. Ai, MD prescribe under Medicare Part D?
In 2024, Weiyun Z. Ai, MD had 673 Medicare Part D claims for 104 beneficiaries; the average among medical oncology physician prescribers was 703. Part D covers Medicare prescriptions only.
What is Weiyun Z. Ai, 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.