Marissa M. Wen, MD
Internal Medicine Physician · Lathrop, CA
Marissa M. Wen, MD is an internal medicine physician with a practice address in Lathrop, California, and NPI 1467999169, issued on Jan 20, 2017. Check the license (California A161459, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Marissa M. Wen
- Credential
- MD
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- A161459 CA
Self-reported in NPPES; status is on the state search - Practice location
- 1507 Garden Farms Ave, Lathrop, CA 95330
- Phone
- (209) 479-8000
- Enumerated
- Jan 20, 2017
- Record last updated
- Jan 21, 2022
- Medicare enrollment
- Enrolled (PECOS I20210514000977); accepts Medicare assignment
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 17,696 in California → Look up another NPI →
Verify Marissa M. Wen in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A161459Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
71% fewer Medicare Part D claims than the average internal medicine physician in 2024
924 Medicare Part D claims for 260 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D.
Most prescribed
- Atorvastatin Calcium78 claims
- Famotidine54 claims
- Furosemide50 claims
- Doxycycline Monohydrate34 claims
- Cefpodoxime Proxetil32 claims
- Metoprolol Succinate31 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 IncModesto, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Marissa M. Wen among 17,696 internal medicine physician records in California
Marissa M. Wen, 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 2017, is newer than 81% of them.
- NPI issued2017 · 81% of these records are older, 16% newer
- In a Medicare fileYes · 79% of these records are
- In the CMS Doctors and Clinicians fileYes · 63% of these records are
- Graduated2003 · median 2004 among the 11,065 with a school on file
- Record last updated2022 · 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).
Internal Medicine Physician providers in California
There are 17,696 internal medicine physician records in California.
All 17,696 in California → Every provider in Lathrop → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Maria Bacay, MDManteca, CA 953361679599070
- Bernard Bacay, MDManteca, CA 953361629094032
- Santokh Bhullar, MDManteca, CA 953361760594105
- Russell Carter, MDManteca, CA 953361528049988
- Terry Croasdale, M.D.Manteca, CA 953361295713147
- M Jacqueline Galang, MDManteca, CA 953361972586097
- Abdul Khan, M.D.Manteca, CA 953361053399980
- Rahul Patel, M.D.Manteca, CA 953361659354868
Common questions
What is Marissa M. Wen, MD's NPI number?
Marissa M. Wen, MD's National Provider Identifier (NPI) is 1467999169, issued on Jan 20, 2017. An NPI identifies a provider in billing; it is not a license.
Where is Marissa M. Wen, MD located?
The NPPES record lists a practice address at 1507 Garden Farms Ave, Lathrop, CA, 95330. Phone: (209) 479-8000. Providers update this record themselves, so call before visiting.
How can I verify Marissa M. Wen, MD's license?
NPPES lists California license number A161459, 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 Marissa M. Wen, MD prescribe under Medicare Part D?
In 2024, Marissa M. Wen, MD had 924 Medicare Part D claims for 260 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.