Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of August 10, 2026.

Dr. Mark George Janczewski, MD, MPH

Individual provider Preventive Medicine/Occupational Environmental Medicine Physician · NPI 1124022843

Dr. Mark George Janczewski, MD, MPH is a Preventive Medicine/Occupational Environmental Medicine Physician in Alexandria, Virginia. Practices as a sole proprietor and works from 2 locations. Licensed in Virginia.

Licensed in
VA
In the registry since
2005
Specialties on file
4
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.
MPH — Master of Public Health
A graduate degree in population health.

See every abbreviation used in this directory →

Practice location Address checks out

425 S Payne St
Alexandria, VA 22314-5944
Phone: (703) 994-7637
Show map & directions

Pin is approximate — placed at the ZIP-code centre, not the exact door.

Additional practice locations (1)

  • 410 Government Ave Ste 1, Valparaiso, FL 32580-1061 — (703) 994-7637

Specialties & licences

Clinical Informatics Physician (primary) Taxonomy 2083C0008X · Licence 0101041106 (VA)
Preventive Medicine/Occupational Environmental Medicine Physician Taxonomy 2083P0500X · Licence 0101041106 (VA)
Family Medicine Physician Taxonomy 207Q00000X · Licence 0101041106 (VA)
Aerospace Medicine Physician Taxonomy 2083A0100X · Licence 0101041106 (VA)

Record details

NPI number1124022843
Entity typeIndividual (Type 1)
GenderMale
Credentials MD , MPH
Sole proprietorYes
NPI enumeratedJune 9, 2005
Last updated in NPPESSeptember 3, 2025
Certification dateSeptember 3, 2025
Mailing address425 S Payne St, Alexandria, VA 22314-5944