NPPES file of Aug 9, 2026

William David Cahill, MD

Internal Medicine Physician · San Francisco, CA

William David Cahill, MD is an internal medicine physician with a practice address in San Francisco, California, and NPI 1366461048, issued on Jul 19, 2006. Check the license (California A90274, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.

Record from CMS NPPES, file of Aug 9, 2026 · Medicare files 2023 and 2024 · method · Verify with CMS →

NPPES recordNPPES file of Aug 9, 2026
1366461048
Name
William David Cahill
Credential
MD
Primary taxonomy
Internal Medicine Physician 207R00000X
License number
A90274 CA
Self-reported in NPPES; status is on the state search
Practice location
50 Lech Walesa, San Francisco, CA 94102
Phone
(415) 554-2727
Enumerated
Jul 19, 2006
Record last updated
Jul 8, 2007 (not updated in 19 years: call before relying on the address or phone)
Medicare enrollment
Enrolled (PECOS I20060919000544); accepts Medicare assignment
Medical or professional school
University Of California, San Francisco School Of Medicine, 2003
Entity
Type 1 · individual
Public record from CMS NPPES (open it on the CMS NPI Registry). Enrollment, assignment, school and telehealth: CMS Doctors and Clinicians file, Aug 2026. A record is not a license: verify it with the state board.
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Also registered at 50 Lech Walesa

A shared address usually means a shared clinic or building; it does not show who employs whom.

  1. Sandra Aseltine, L.C.S.W.Clinical Social Worker1023134798
  2. Deborah Borne, MDFamily Medicine Physician1598892580
  3. Ann Dallman, MDPublic Health & General Preventive Medicine Physician1821146564
  4. Margaret Farny, RN, RASRegistered Nurse1922153097
  5. Evan Filler, D.M.D.Dentist1447466479
  6. Meredith Florian, NP MSNPrimary Care Nurse Practitioner1407983497

Verify William David Cahill in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersMedical Board of California
    Search for license A90274
    Check the board
  3. 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
  4. 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
  5. 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
Open the California license search

PlainDoctor does not match the HHS-OIG exclusion list to individual records: most entries carry no NPI. Search the OIG exclusion list by name.

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91% fewer Medicare Part D claims than the average internal medicine physician in 2024

284 Medicare Part D claims for 73 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. 12 claims were for opioids.

  1. William Cahill284
  2. Specialty average3,176

Most prescribed

  1. Atorvastatin Calcium24 claims
  2. Amlodipine Besylate21 claims
  3. Losartan Potassium12 claims
  4. Gabapentin11 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): 97.2 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.

  1. Qualityout of 100 · 30% of the final score88.3
  2. Costout of 100 · 30%69.5
  3. Promoting interoperabilityout of 100 · 25%100.0
  4. Improvement activities40 of 40 points · 15%100.0

Source: CMS Quality Payment Program, MIPS performance year 2023, group reporting; category weights for 2023 (qpp.cms.gov).

Bills Medicare through one group practice

  1. Pacific Inpatient Medical GroupSan Francisco, CA

Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (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.

Other internal medicine physician records in California

  1. Jacob Aaron, MDSan Francisco, CA1407202518
  2. Alistair Aaronson, MDStanford, CA1457628760
  3. Jose Abad., MDSacramento, CA1144607219
  4. Donna Abare, MDOakland, CA1386722155
  5. Marce AbareScotts Valley, CA1457744708
  6. Samuel Abarte, M.D.Chula Vista, CA1578535498
  7. Alexander Abary, MDLong Beach, CA1104995919
  8. Luba Abascal, MDSan Francisco, CA1023180874
  9. Michael Abate, MDSacramento, CA1548248131
  10. Wali Abawi, D.O.Joshua Tree, CA1104362268

Common questions

What is William David Cahill, MD's NPI number?

William David Cahill, MD's National Provider Identifier (NPI) is 1366461048, issued on Jul 19, 2006. An NPI identifies a provider in billing; it is not a license.

Where is William David Cahill, MD located?

The NPPES record lists a practice address at 50 Lech Walesa, San Francisco, CA, 94102. Phone: (415) 554-2727. Providers update this record themselves, so call before visiting.

How can I verify William David Cahill, MD's license?

NPPES lists California license number A90274, 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 William David Cahill, MD prescribe under Medicare Part D?

In 2024, William David Cahill, MD had 284 Medicare Part D claims for 73 beneficiaries; the average among internal medicine physician prescribers was 3,176. Part D covers Medicare prescriptions only.

What is William David Cahill, MD's MIPS final score?

The 2023 MIPS final score is 97.2 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.