Brock Alan Webster Macdonald, M.D.
Gastroenterology Physician · San Francisco, CA
Brock Alan Webster Macdonald, M.D. is a gastroenterology physician with a practice address in San Francisco, California, and NPI 1689901506, issued on Nov 13, 2009. Check the license (California A102304, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Brock Alan Webster Macdonald
- Credential
- M.D.
- Primary taxonomy
- Gastroenterology Physician 207RG0100X
- License number
- A102304 CA
Self-reported in NPPES; status is on the state search - Practice location
- 350 Parnassus Ave, San Francisco, CA 94117
- Phone
- (415) 476-2777
- Enumerated
- Nov 13, 2009
- Record last updated
- Dec 15, 2021 (not updated in 5 years: call before relying on the address or phone)
- Medicare enrollment
- Enrolled (PECOS I20111115000602); accepts Medicare assignment
- Medical or professional school
- Columbia University College Of Physicians And Surgeons, 2004
- Entity
- Type 1 · individual
8 nearest gastroenterology physician records → All 2,140 in California → Look up another NPI →
Also registered at 350 Parnassus Ave
A shared address usually means a shared clinic or building; it does not show who employs whom.
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Verify Brock Alan Webster Macdonald in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A102304Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
38% more Medicare Part D claims than the average gastroenterology physician in 2024
1,123 Medicare Part D claims for 618 beneficiaries, against an average of 811 among the 16,445 providers of this specialty who prescribed in Part D. Brand-name drugs were 10% of claims.
Most prescribed
- Gavilyte-C413 claims
- Omeprazole144 claims
- Pantoprazole Sodium78 claims
- Budesonide Dr56 claims
- Carvedilol54 claims
- Mesalamine52 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.
Industry payments in 2024: $29.75
1 payment: food and beverage; the largest payer was CapsoVision, Inc. The 13,350 providers of this specialty with any payment received $5,015.95 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 one group practice
- Permanente Medical Group IncStockton, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Brock Alan Webster Macdonald among 2,140 gastroenterology physician records in California
Brock Alan Webster Macdonald, M.D. is one of 2,140 gastroenterology physician records with a practice address in California. 83% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2009, is newer than 69% of them.
- NPI issued2009 · 69% of these records are older, 28% newer
- In a Medicare fileYes · 83% of these records are
- In the CMS Doctors and Clinicians fileYes · 72% of these records are
- Graduated2004 · median 2002 among the 1,538 with a school on file
- Record last updated2021 · 60% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RG0100X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Gastroenterology Physician providers in California
There are 2,140 gastroenterology physician records in California.
All 2,140 in California → Every provider in San Francisco → Gastroenterology Physician nationwide →
The 8 gastroenterology physician records with the nearest ZIP codes
- James Ostroff, MDSan Francisco, CA 941171477505881
- Harvey Watts, M.D.San Francisco, CA 941171184640872
- Wing Kam, M.D., PH.D.San Francisco, CA 941181003964826
- Dean Rider, MDSan Francisco, CA 941181487759296
- Zealous Wiley, MDOakland, CA 941161740232610
- Waseem Ahmad, M.D.San Francisco, CA 941151649633991
- Timothy Chen, M.D.San Francisco, CA 941151699017707
- Charlotte Ching, MDSan Francisco, CA 941151407475312
Common questions
What is Brock Alan Webster Macdonald, M.D.'s NPI number?
Brock Alan Webster Macdonald, M.D.'s National Provider Identifier (NPI) is 1689901506, issued on Nov 13, 2009. An NPI identifies a provider in billing; it is not a license.
Where is Brock Alan Webster Macdonald, M.D. located?
The NPPES record lists a practice address at 350 Parnassus Ave, San Francisco, CA, 94117. Phone: (415) 476-2777. Providers update this record themselves, so call before visiting.
How can I verify Brock Alan Webster Macdonald, M.D.'s license?
NPPES lists California license number A102304, 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 Brock Alan Webster Macdonald, M.D. prescribe under Medicare Part D?
In 2024, Brock Alan Webster Macdonald, M.D. had 1,123 Medicare Part D claims for 618 beneficiaries; the average among gastroenterology physician prescribers was 811. 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.