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

Dr. Mary Lynn Nielsen, MD

Individual provider Psychiatry Physician · NPI 1972645240

Dr. Mary Lynn Nielsen, MD is a Psychiatry Physician in Clayton, Missouri. Practices as a sole proprietor. Licensed in Missouri.

Licensed in
MO
In the registry since
2007
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

225 S Meramec Ave Ste 932T
Clayton, MO 63105-3511
Phone: (314) 721-7550
Fax: (314) 863-2114
Show map & directions

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

Specialties & licences

Psychiatry Physician (primary) Taxonomy 2084P0800X · Licence MDR7P10 (MO)

Record details

NPI number1972645240
Entity typeIndividual (Type 1)
GenderFemale
Credentials MD
Sole proprietorYes
NPI enumeratedFebruary 13, 2007
Last updated in NPPESJuly 8, 2007

Other providers in Clayton