Medical emergency?Emergency? Call 911. Nearest emergency roomsNearest ERs

Obstetrics/Gynecology

Margaret Gray Swain, MD

Works at hospitals in Saint Louis, MO · Missouri

Summary

Dr. Margaret Gray Swain, MD is an OB-GYN at 1110 Highlands Plaza Dr E, Saint Louis, MO 63110. Phone: (314) 273-0195. Accepts Medicare assignment. In 2024, Margaret Gray Swain had 30 Original Medicare patients and 58 services. NPI 1245267178. 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 Margaret Gray Swain, 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 Margaret Gray Swain accept Medicare assignment?
Yes. Medicare's clinician data says Margaret Gray Swain 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 Margaret Gray Swain see?
In 2024, CMS data shows 30 Original Medicare patients and 58 services for Margaret Gray Swain. This counts Original Medicare only and measures volume, not quality.
What is Margaret Gray Swain's NPI number?
1245267178. 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 Margaret Gray Swain, 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 patients30
Services billed to Medicare58
Different services or procedures19
Participating Medicare providerYes
Average age of these patients67

Most frequent services

  1. Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)19 services
  2. Cervical or vaginal cancer screening; pelvic and clinical breast examination (G0101)11 services

Chronic conditions among these patients

Share of this clinician’s Original Medicare patients with each condition, as published by CMS (it describes the patients, not the care given).

  • High cholesterol63%
  • High blood pressure57%
  • Arthritis57%

Hospitals where Margaret Gray Swain works

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

Group practices

Medicare enrollment lists Margaret Gray Swain as a member of this group (CMS data updated October 2, 2026).

  • Physician Groups LC521 clinicians in the group

Specialties

Find other Obstetrics/Gynecology doctors in Missouri →

Other OB-GYNs in Saint Louis

Clinicians with the same Medicare primary specialty in Saint Louis, MO — not a recommendation.

All OB-GYNs in Saint Louis →

Other clinicians in Physician Groups LC

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

Clinician information

CredentialMD
Medical schoolWashington University School Of Medicine
Graduation year2002 (24 years since medical school)
Gender (as listed)Female
Medicare assignmentAccepts (Medicare-approved amount as full payment)
NPI (National Provider Identifier)1245267178
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