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

Neurology

Theresa B. Sevilis, DO

Works at hospitals in Orlando, FL · Tyler, TX · Bradenton, FL … · Florida, Texas

Summary

Dr. Theresa B. Sevilis, DO is a neurologist at 1000 Montauk Hwy, West Islip, NY 11795. Phone: (631) 376-3000. Accepts Medicare assignment. In 2024, Theresa B. Sevilis had 200 Original Medicare patients and 201 services. NPI 1407111461. 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 Theresa B. Sevilis, 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 Theresa B. Sevilis accept Medicare assignment?
Yes. Medicare's clinician data says Theresa B. Sevilis 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 Theresa B. Sevilis see?
In 2024, CMS data shows 200 Original Medicare patients and 201 services for Theresa B. Sevilis. This counts Original Medicare only and measures volume, not quality.
What is Theresa B. Sevilis's NPI number?
1407111461. 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 Theresa B. Sevilis, 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 patients200
Services billed to Medicare201
Different services or procedures18
Participating Medicare providerYes
Average age of these patients77

Most frequent services

  1. Telehealth consultation, emergency department or initial inpatient, typically 30 minutes communicating with the patient via telehealth (G0425)73 services
  2. Telehealth consultation, emergency department or initial inpatient, typically 50 minutes communicating with the patient via telehealth (G0426)47 services
  3. Telehealth consultation, critical care, initial , physicians typically spend 60 minutes communicating with the patient and providers via telehealth (G0508)41 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 blood pressure75%
  • High cholesterol75%
  • Stroke or mini-stroke75%
  • Arthritis58%
  • Ischemic heart disease54%
  • Anxiety44%

Hospitals where Theresa B. Sevilis works

Medicare's Facility Affiliation Data lists Theresa B. Sevilis 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 Theresa B. Sevilis is enrolled with Medicare (CMS data updated October 2, 2026). The first 5 of 15; the Medicare profile lists all.

Group practices

Medicare enrollment lists Theresa B. Sevilis as a member of these groups (CMS data updated October 2, 2026).

  • Baptist Health Medical Group Inc2,472 clinicians in the group
  • Lee Health System Inc1,428 clinicians in the group
  • NCHMD Inc510 clinicians in the group
  • Piedmont Hospitalist Physicians LLC508 clinicians in the group
  • Meritas Health Corporation502 clinicians in the group
  • St. Joseph Hospital of Nashua NH273 clinicians in the group

Specialties

Find other Neurology doctors in New York →

Other neurologists in West Islip

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

All neurologists in West Islip →

Other clinicians in Baptist Health Medical Group Inc

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

Clinician information

CredentialDO
Graduation year2011 (15 years since medical school)
Gender (as listed)Female
Medicare assignmentAccepts (Medicare-approved amount as full payment)
TelehealthOffers telehealth services
NPI (National Provider Identifier)1407111461
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