James Waterhouse, M.D.
Internal Medicine Physician · San Leandro, CA
James Waterhouse, M.D. is an internal medicine physician with a practice address in San Leandro, California, and NPI 1881772630, issued on Nov 1, 2006. Check the license (California G57842, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- James Waterhouse
- Credential
- M.D.
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- G57842 CA
Self-reported in NPPES; status is on the state search - Practice location
- 2500 Merced St, San Leandro, CA 94577
- Phone
- (510) 454-1000
- Enumerated
- Nov 1, 2006
- Record last updated
- Nov 30, 2021 (not updated in 5 years: call before relying on the address or phone)
- Medicaid ID
- 00G578420 CA
- Medicare enrollment
- Enrolled (PECOS I20110113000195); accepts Medicare assignment
- Medical or professional school
- University Of Tennessee, Hsc, College Of Medicine, 1984
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 17,696 in California → Look up another NPI →
Also registered at 2500 Merced St
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Verify James Waterhouse in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license G57842Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
2.1 times the Medicare Part D claims of the average internal medicine physician in 2024
6,759 Medicare Part D claims for 524 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 10% of claims. 457 claims were for opioids.
Most prescribed
- Atorvastatin Calcium536 claims
- Amlodipine Besylate318 claims
- Lisinopril311 claims
- Atenolol290 claims
- Losartan Potassium236 claims
- Hydrocodone-Acetaminophen227 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.
Bills Medicare through one group practice
- Permanente Medical Group IncSan Leandro, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
James Waterhouse among 17,696 internal medicine physician records in California
James Waterhouse, M.D. 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 2006, is newer than 5% of them.
- NPI issued2006 · 5% of these records are older, 56% newer
- In a Medicare fileYes · 79% of these records are
- In the CMS Doctors and Clinicians fileYes · 63% of these records are
- Graduated1984 · median 2004 among the 11,065 with a school on file
- Record last updated2021 · 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).
62 internal medicine physician records list a practice address in San Leandro
They are 62 of the 4,976 NPPES records with a practice address in San Leandro, and 17,696 internal medicine physician records in California.
All 17,696 in California → Every provider in San Leandro → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Abhijan Banerjee, M.D.San Leandro, CA 945771548292113
- Leo Chi, M.D.San Leandro, CA 945771467530220
- Young Choi, D.O.San Leandro, CA 945771871671628
- Christian Dang, M.D.San Leandro, CA 945771417986753
- Louis Edelson, M.D.San Leandro, CA 945771356429120
- Mei Kung, M.D.San Leandro, CA 945771407939465
- Sandeep Lal, M.D.San Leandro, CA 945771558448340
- Evelyn Nakagawa, M.D.San Leandro, CA 945771023077294
Common questions
What is James Waterhouse, M.D.'s NPI number?
James Waterhouse, M.D.'s National Provider Identifier (NPI) is 1881772630, issued on Nov 1, 2006. An NPI identifies a provider in billing; it is not a license.
Where is James Waterhouse, M.D. located?
The NPPES record lists a practice address at 2500 Merced St, San Leandro, CA, 94577. Phone: (510) 454-1000. Providers update this record themselves, so call before visiting.
How can I verify James Waterhouse, M.D.'s license?
NPPES lists California license number G57842, 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 James Waterhouse, M.D. prescribe under Medicare Part D?
In 2024, James Waterhouse, M.D. had 6,759 Medicare Part D claims for 524 beneficiaries; the average among internal medicine physician prescribers was 3,176. 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.