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

Delwyn Lee Lassen, MD

Individual provider Family Medicine Physician · NPI 1558346015

Delwyn Lee Lassen, MD is a Family Medicine Physician in Sioux Center, Iowa. Works from 2 locations. Licensed in Iowa.

Licensed in
IA
In the registry since
2005
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

33 4th St NW
Sioux Center, IA 51250-1870
Phone: (712) 722-1700
Fax: (712) 722-1770
Show map & directions

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

Additional practice locations (1)

  • 2501 Pierce St, Sioux City, IA 51104-3725 — (712) 294-5000

Specialties & licences

Family Medicine Physician (primary) Taxonomy 207Q00000X · Licence 21150 (IA)

Record details

NPI number1558346015
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedDecember 7, 2005
Last updated in NPPESDecember 15, 2020
Certification dateDecember 15, 2020

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