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Cardiovascular Disease (Cardiology)

Marysia S. Tweet, MD

Works at hospitals in Rochester, MN · Minnesota

Summary

Dr. Marysia S. Tweet, MD is a cardiologist at 1216 2nd St SW, Rochester, MN 55902. Phone: (507) 255-5123. Accepts Medicare assignment. In 2024, Marysia S. Tweet had 46 Original Medicare patients and 96 services. NPI 1821254939. 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.

  • Specialty: Cardiologist (Medicare lists Cardiovascular Disease (Cardiology))
  • Address: 1216 2nd St SW, Rochester, MN 55902 · Directions (1 more location)
  • Phone: (507) 255‑5123
  • Medicare: Accepts Medicare assignment
  • Hospital: Mayo Clinic Hospital Rochester
  • Group practice: Mayo Clinic
  • Medical school: University Of Minnesota Medical School · graduated 2008 (18 years since medical school)
  • Gender (as listed): Female
  • Telehealth: offered

From official Medicare data

This page shows what Medicare's official clinician data says about Marysia S. Tweet, 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 Marysia S. Tweet accept Medicare assignment?
Yes. Medicare's clinician data says Marysia S. Tweet 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 Marysia S. Tweet see?
In 2024, CMS data shows 46 Original Medicare patients and 96 services for Marysia S. Tweet. This counts Original Medicare only and measures volume, not quality.
What is Marysia S. Tweet's NPI number?
1821254939. 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 Marysia S. Tweet, 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 patients46
Services billed to Medicare96
Different services or procedures10
Participating Medicare providerYes
Average age of these patients78

Most frequent services

  1. Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes (99232)30 services
  2. Established patient office or other outpatient visit with high level of medical decision making, if using time, 40 minutes or more (99215)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 blood pressure75%
  • High cholesterol75%
  • Ischemic heart disease74%
  • Chronic kidney disease52%
  • Atrial fibrillation48%
  • Arthritis41%

Hospitals where Marysia S. Tweet works

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

Group practices

Medicare enrollment lists Marysia S. Tweet as a member of this group (CMS data updated October 2, 2026).

  • Mayo Clinic4,956 clinicians in the group

Specialties

Find other Cardiovascular Disease (Cardiology) doctors in Minnesota →

Other cardiologists in Rochester

Clinicians with the same Medicare primary specialty in Rochester, MN — not a recommendation.

All cardiologists in Rochester →

Other clinicians in Mayo Clinic

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

Clinician information

CredentialMD
Medical schoolUniversity Of Minnesota Medical School
Graduation year2008 (18 years since medical school)
Gender (as listed)Female
Medicare assignmentAccepts (Medicare-approved amount as full payment)
TelehealthOffers telehealth services
NPI (National Provider Identifier)1821254939
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