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

Dr. Lukejohn Welch Day, MD

Individual provider Gastroenterology Physician · NPI 1669623773

Dr. Lukejohn Welch Day, MD is a Gastroenterology in San Francisco, California. Graduated from Stanford University School of Medicine in 2004, 22 years ago. Practices with UCSF Medical Group Business Services, a 1,531-clinician group and accepts Medicare assignment. Licensed in California.

Years since qualifying
22
Trained at
Stanford University School of Medicine
Licensed in
CA
In the registry since
2008
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

505 Parnassus Ave
San Francisco, CA 94143-2204
Phone: (415) 377-2176
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Gastroenterology Physician (primary) Taxonomy 207RG0100X · Licence A93534 (CA)

Record details

NPI number1669623773
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorYes
NPI enumeratedOctober 7, 2008
Last updated in NPPESOctober 7, 2008

Medicare enrollment

From the CMS Doctors & Clinicians file — this clinician is enrolled in Medicare.

Medicare specialtyGASTROENTEROLOGY
Also practisesINTERNAL MEDICINE
Medical schoolSTANFORD UNIVERSITY SCHOOL OF MEDICINE
Graduated 2004 (22 years in practice)
Group practice Ucsf Medical Group Business Services — 1531 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
Practice locations2 on file with Medicare

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