Brian Karaszewski, M.D.
NPI 1255478376 · Internal Medicine Physician · Williamsville, NY
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Brian Karaszewski, M.D. is a Internal Medicine Physician provider in Williamsville, NY (NPI 1255478376).
Provider details
- NPI number
- 1255478376
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- Yes
- License
- 213340-1 (NY)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
19 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)25% of score
528 Medicare services, 2024 (ranked within specialty)
- Open Payments transparency10% of score
Has Open Payments disclosures (2024)
Medicare volume is ranked against active providers in the same specialty. Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our .
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Management Using the Results of Remote Vital Sign Monitoring Per Calendar Month, First 20 Minutes99457 | 183 | $46 |
| Annual Wellness Visit, Includes a Personalized Prevention Plan of Service (pps), Subsequent VisitG0439 | 142 | $122 |
| Remote Monitoring of Physiologic Parameters, Initial Supply of Devices With Daily Recordings Or Programmed Alerts Transmission, Each 30 Days99454 | 111 | $44 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 71 | $85 |
| Injection of Drug Or Substance Under Skin Or Into Muscle96372 | 21 | $13 |
Typical Medicare-allowed amounts for these services range $13–$122 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, and not what you would be billed. Medicare Part B covers roughly an eighth of all NPIs (65+ skew); services with fewer than 11 beneficiaries are suppressed by CMS. Source: CMS Medicare Physician & Other Practitioners, by Provider & Service.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 174 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Levothyroxine Sodium | 862 | 237 |
| Amlodipine Besylate | 518 | 136 |
| Rosuvastatin Calcium | 490 | 149 |
| Atorvastatin Calcium | 459 | 135 |
| Omeprazole | 393 | 96 |
| Lisinopril | 371 | 102 |
| Pantoprazole Sodium |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$4,110 across 213 records (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Registry dates
- Enumerated
- 2007-01-30
- Last updated
- 2019-08-19
Frequently asked questions
- What is Brian Karaszewski's NPI number?
- Brian Karaszewski's National Provider Identifier (NPI) is 1255478376, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Brian Karaszewski's specialty?
- Brian Karaszewski is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Brian Karaszewski located?
- Brian Karaszewski's practice location on file with NPPES is 400 International Dr., Williamsville, NY 14221.
- What is Brian Karaszewski's phone number?
- The practice phone number listed in the NPPES registry for Brian Karaszewski is (716) 631-3555.
- Does Brian Karaszewski accept Medicare?
- Brian Karaszewski is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Brian Karaszewski's NPI active?
- Yes — Brian Karaszewski's NPI (1255478376) is active in the NPPES registry as of the last update on 2019-08-19.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.