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Obstetrics/Gynecology

Michelle Marieni, MD

Works at hospitals in San Francisco, CA · California

Summary

Dr. Michelle Marieni, MD is an OB-GYN at 1580 Valencia St, Suite 508, San Francisco, CA 94110. Phone: (415) 641-6996. Accepts Medicare assignment. In 2024, Michelle Marieni had 14 Original Medicare patients and 17 services. NPI 1942731278. Source: CMS National Downloadable File, updated October 2, 2026; CMS Facility Affiliation Data, updated October 2, 2026; CMS Medicare Physician & Other Practitioners, data year 2024.

From official Medicare data

This page shows what Medicare's official clinician data says about Michelle Marieni, joined by NPI number (data updated October 2, 2026). It is not a recommendation or a rating. Call the office or hospital to confirm before you go.

In a medical emergency, call 911.

Quick answers

Does Michelle Marieni accept Medicare assignment?
Yes. Medicare's clinician data says Michelle Marieni accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of October 2, 2026. Ask the office to confirm before your visit.
How many Medicare patients does Michelle Marieni see?
In 2024, CMS data shows 14 Original Medicare patients and 17 services for Michelle Marieni. This counts Original Medicare only and measures volume, not quality.
What is Michelle Marieni's NPI number?
1942731278. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.

Medicare activity in 2024

Official CMS public-use data for Michelle Marieni, data year 2024 (released May 21, 2026). It covers Original Medicare (fee-for-service) patients only, not Medicare Advantage or other insurance. It shows volume, not quality or outcomes. CMS hides any count of 10 or fewer patients.

Original Medicare patients14
Services billed to Medicare17
Different services or procedures6
Participating Medicare providerYes
Average age of these patients73

Hospitals where Michelle Marieni works

Medicare's Facility Affiliation Data lists Michelle Marieni at these hospitals (updated October 2, 2026). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians. Star rating and emergency services: Hospital General Information (CMS), data updated October 26, 2026.

Practice locations

Addresses where Michelle Marieni is enrolled with Medicare (CMS data updated October 2, 2026).

Group practices

Medicare enrollment lists Michelle Marieni as a member of this group (CMS data updated October 2, 2026).

  • Sutter Bay Hospitals48 clinicians in the group

Specialties

Find other Obstetrics/Gynecology doctors in California →

Other OB-GYNs in San Francisco

Clinicians with the same Medicare primary specialty in San Francisco, CA — not a recommendation.

All OB-GYNs in San Francisco →

Other clinicians in Sutter Bay Hospitals

Medicare enrollment lists these clinicians in the same group practice — not a recommendation.

Clinician information

CredentialMD
Medical schoolCreighton University School Of Medicine
Graduation year2017 (9 years since medical school)
Gender (as listed)Female
Medicare assignmentAccepts (Medicare-approved amount as full payment)
NPI (National Provider Identifier)1942731278
CorrectionsReport an error or suggest an update →

Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.

Sources

  1. Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated October 2, 2026, retrieved October 29, 2026
  2. Hospital General Information — CMS, data updated October 26, 2026, retrieved November 13, 2026
  3. National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
  4. Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
  5. NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
  6. Medicare Care Compare — official Medicare tool to look up clinicians