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Obstetrics/Gynecology

Karen Greiner, MD

Works at hospitals in San Diego, CA · California

Summary

Dr. Karen Greiner, MD is an OB-GYN at 15 Grumman Rd, Suite 1400, Bethpage, NY 11714. May accept Medicare assignment. NPI 1427686930. Source: CMS National Downloadable File, updated October 2, 2026; CMS Facility Affiliation Data, updated October 2, 2026.

  • Specialty: OB-GYN (Medicare lists Obstetrics/Gynecology)
  • Address: 15 Grumman Rd, Suite 1400, Bethpage, NY 11714 · Directions (2 more locations)
  • Medicare: May accept Medicare assignment
  • Hospital: UC San Diego Health Hillcrest - Hillcrest Medical Center
  • Medical school: Oregon Health Sciences University School Of Medicine · graduated 2020 (6 years since medical school)
  • Gender (as listed): Female
NPI Registry record Medicare profile

From official Medicare data

This page shows what Medicare's official clinician data says about Karen Greiner, 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 Karen Greiner accept Medicare assignment?
Medicare's clinician data says Karen Greiner may accept Medicare assignment (as of October 2, 2026). Ask the office whether they accept it for your visit.
What is Karen Greiner's NPI number?
1427686930. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.

Hospitals where Karen Greiner works

Medicare's Facility Affiliation Data lists Karen Greiner 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 Karen Greiner is enrolled with Medicare (CMS data updated October 2, 2026).

  • 15 Grumman Rd, Suite 1400Bethpage, NY 11714
  • 6200 Greenwich DrSan Diego, CA 92122
  • File No, Suite 57326Los Angeles, CA 90074

Specialties

Find other Obstetrics/Gynecology doctors in New York →

Other OB-GYNs in Bethpage

Clinicians with the same Medicare primary specialty in Bethpage, NY — not a recommendation.

All OB-GYNs in Bethpage →

Clinician information

CredentialMD
Medical schoolOregon Health Sciences University School Of Medicine
Graduation year2020 (6 years since medical school)
Gender (as listed)Female
Medicare assignmentMay accept for some services
NPI (National Provider Identifier)1427686930
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. NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
  5. Medicare Care Compare — official Medicare tool to look up clinicians