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

Dr. William Grant Day, MD

Individual provider Allergy & Immunology Physician · NPI 1740745041

Dr. William Grant Day, MD is an Allergy & Immunology Physician in Portsmouth, Virginia. Practices as a sole proprietor. Licensed in Virginia.

Licensed in
VA
In the registry since
2019
Specialties on file
2
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

See every abbreviation used in this directory →

Practice location Address checks out

620 John Paul Jones Cir Ste 275
Portsmouth, VA 23708-2197
Phone: (757) 953-2000
Show map & directions

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

Specialties & licences

Allergy & Immunology Physician (primary) Taxonomy 207K00000X · Licence 0101271195 (VA)
Internal Medicine Physician Taxonomy 207R00000X · Licence 0101271195 (VA)

Record details

NPI number1740745041
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorYes
NPI enumeratedJanuary 31, 2019
Last updated in NPPESJune 30, 2026
Certification dateJune 30, 2026