Individual Healthcare Provider
Mark George Janczewski, MD, MPH
Provider's NPPES record last updated: September 3, 2025
Overview
- Entity Type
- Individual Healthcare Provider
- NPI
- 1124022843
- Primary Specialty
- Preventive Medicine — Clinical Informatics
- Practice Location
- Alexandria, Virginia
- Sole Proprietor
- Yes
Federal Screening
NPISignal checked this NPI against federal exclusion sources. Results below are based on the NPI number itself — an identifier match, not a name match.
List of Excluded Individuals/Entities (LEIE)
HHS Office of Inspector General
No potential match was identified in NPISignal's indexed List of Excluded Individuals/Entities (LEIE) records as of 2026-09-10.
- Source data
- September 10, 2026
- Records indexed
- 84,001
- Screened
- Sep 17, 2026, 11:51 PM UTC
This reflects only the records NPISignal currently holds and the identity information supplied. It is not a verification of eligibility, licensure, or compliance. Verify decisions that matter against the authoritative source.
SAM.gov Exclusions
U.S. General Services Administration
SAM.gov Exclusions was not checked.
SAM.gov screening is not configured on this deployment. No SAM check has been performed.
- Screened
- Not checked
This is an NPI-based check only. NPISignal does not publish name-based exclusion matches on a provider profile. A shared or similar name is a lead that requires human review, not an identification, and this page is not the place to make one. Run a name-based screening below to see potential matches with the reasons for each.
This reflects only the records NPISignal currently holds and the identity information supplied. It is not a verification of eligibility, licensure, or compliance. Verify decisions that matter against the authoritative source.
Searches OIG LEIE and SAM.gov by name and reviews every potential match.
Specialties & Taxonomies
- Primary
Preventive Medicine
Clinical Informatics
Allopathic & Osteopathic Physicians
Physicians who practice Clinical Informatics collaborate with other health care and information technology professionals to analyze, design, implement and evaluate information and communication systems that enhance individual and population health outcomes, improve patient care, and strengthen the clinician-patient relationship. Clinical Informaticians use their knowledge of patient care combined with their understanding of informatics concepts, methods, and tools to: assess information and knowledge needs of health care professionals and patients; characterize, evaluate, and refine clinical processes; develop, implement, and refine clinical decision support systems; and lead or participate in the procurement, customization, development, implementation, management, evaluation, and continuous improvement of clinical information systems.
Taxonomy code 2083C0008X Preventive Medicine
Preventive Medicine/Occupational Environmental Medicine
Allopathic & Osteopathic Physicians
A preventive medicine physician who specializes in preventive medicine/occupational-environmental medicine, which is focused on protecting the population from occupational and environmental conditions.
Taxonomy code 2083P0500XFamily Medicine
Allopathic & Osteopathic Physicians
Family Medicine is the medical specialty which is concerned with the total health care of the individual and the family. It is the specialty in breadth which integrates the biological, clinical, and behavioral sciences. The scope of family medicine is not limited by age, sex, organ system, or disease entity.
Taxonomy code 207Q00000XPreventive Medicine
Aerospace Medicine
Allopathic & Osteopathic Physicians
Aerospace medicine focuses on the clinical care, research, and operational support of the health, safety, and performance of crewmembers and passengers of air and space vehicles, together with the support personnel who assist operation of such vehicles. This population often works and lives in remote, isolated, extreme, or enclosed environments under conditions of physical and psychological stress. Practitioners strive for an optimal human-machine match in occupational settings rich with environmental hazards and engineering countermeasures.
Taxonomy code 2083A0100X
Provider-Reported License Information
- Preventive Medicine (Virginia)
- 0101041106
- Preventive Medicine (Virginia)
- 0101041106
- Family Medicine (Virginia)
- 0101041106
- Preventive Medicine (Virginia)
- 0101041106
Practice Locations
Practice Location
425 S Payne St
Alexandria, Virginia 22314-5944
Phone: (703) 994-7637
Additional Practice Location
410 Government Ave Ste 1
Valparaiso, Florida 32580-1061
Phone: (703) 994-7637
Record Information
- Enumeration Date
- June 9, 2005
- Provider's NPPES Record Last Updated
- September 3, 2025
- Certification Date
- September 3, 2025
- NPISignal NPPES Dataset
- August 2026
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