Stephen C. Lazarus, MD
Internal Medicine Physician · San Francisco, CA
Stephen C. Lazarus, MD is an internal medicine physician with a practice address in San Francisco, California, and NPI 1659324531, issued on May 19, 2006. Check the license (California A25354, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Stephen C. Lazarus
- Credential
- MD
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- A25354 CA
Self-reported in NPPES; status is on the state search - Practice location
- 400 Parnassus Ave, San Francisco, CA 94143
- Phone
- (415) 353-2961
- Enumerated
- May 19, 2006
- Record last updated
- Jun 12, 2008 (not updated in 18 years: call before relying on the address or phone)
- Fax
- (415) 353-2568
- Medicaid ID
- 00A253540 CA
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 17,696 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.
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Verify Stephen C. Lazarus in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A25354Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
97% fewer Medicare Part D claims than the average internal medicine physician in 2024
93 Medicare Part D claims for 27 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 82% of claims.
Most prescribed
- Albuterol Sulfate Hfa23 claims
- Spiriva Respimat23 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).
Stephen C. Lazarus among 17,696 internal medicine physician records in California
Stephen C. Lazarus, 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 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 fileNo · 63% of these records are
- Record last updated2008 · 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 →
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Common questions
What is Stephen C. Lazarus, MD's NPI number?
Stephen C. Lazarus, MD's National Provider Identifier (NPI) is 1659324531, issued on May 19, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Stephen C. Lazarus, MD located?
The NPPES record lists a practice address at 400 Parnassus Ave, San Francisco, CA, 94143. Phone: (415) 353-2961. Providers update this record themselves, so call before visiting.
How can I verify Stephen C. Lazarus, MD's license?
NPPES lists California license number A25354, 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 Stephen C. Lazarus, MD prescribe under Medicare Part D?
In 2024, Stephen C. Lazarus, MD had 93 Medicare Part D claims for 27 beneficiaries; the average among internal medicine physician prescribers was 3,176. Part D covers Medicare prescriptions only.
What is Stephen C. Lazarus, 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.