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.

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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
Mailing address620 John Paul Jones Cir, Portsmouth, VA 23708-2111