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Emergency Medicine

Brittany L. Grzybowski, MD

Works at hospitals in Pasadena, CA · California

Summary

Dr. Brittany L. Grzybowski, MD is an emergency medicine doctor at 100 W California Blvd, Pasadena, CA 91105. Accepts Medicare assignment. In 2024, Brittany L. Grzybowski had 344 Original Medicare patients and 530 services. NPI 1598127128. 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: Emergency medicine doctor (Medicare lists Emergency Medicine)
  • Address: 100 W California Blvd, Pasadena, CA 91105 · Directions
  • Medicare: Accepts Medicare assignment
  • Hospital: Huntington Hospital
  • Group practice: HMH Emergency Medical Group, Inc.
  • Medical school: New York University School Of Medicine · graduated 2016 (10 years since medical school)
  • Gender (as listed): Female

From official Medicare data

This page shows what Medicare's official clinician data says about Brittany L. Grzybowski, 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 Brittany L. Grzybowski accept Medicare assignment?
Yes. Medicare's clinician data says Brittany L. Grzybowski 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 Brittany L. Grzybowski see?
In 2024, CMS data shows 344 Original Medicare patients and 530 services for Brittany L. Grzybowski. This counts Original Medicare only and measures volume, not quality.
What is Brittany L. Grzybowski's NPI number?
1598127128. 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 Brittany L. Grzybowski, 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 patients344
Services billed to Medicare530
Different services or procedures51
Participating Medicare providerYes
Average age of these patients76

Most frequent services

  1. Emergency department visit with high level of medical decision making (99285)207 services
  2. Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report only (93010)123 services
  3. Emergency department visit with moderate level of medical decision making (99284)40 services
  4. Critical care, first 30-74 minutes (99291)24 services
  5. Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes (99223)13 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%
  • Arthritis60%
  • Diabetes47%
  • Ischemic heart disease44%
  • Chronic kidney disease39%

Hospitals where Brittany L. Grzybowski works

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

Group practices

Medicare enrollment lists Brittany L. Grzybowski as a member of this group (CMS data updated October 2, 2026).

  • HMH Emergency Medical Group, Inc.60 clinicians in the group

Specialties

Find other Emergency Medicine doctors in California →

Other emergency medicine doctors in Pasadena

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

All emergency medicine doctors in Pasadena →

Other clinicians in HMH Emergency Medical Group, Inc.

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

Clinician information

CredentialMD
Medical schoolNew York University School Of Medicine
Graduation year2016 (10 years since medical school)
Gender (as listed)Female
Medicare assignmentAccepts (Medicare-approved amount as full payment)
NPI (National Provider Identifier)1598127128
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