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

Mark L. Collister, LSW

Individual provider Social Worker · NPI 1225078082

Mark L. Collister, LSW is a Social Worker in Williamsport, Pennsylvania. Licensed in Pennsylvania. Registered with an NPI since 2006.

Licensed in
PA
In the registry since
2006
What do these letters mean?
LSW — Licensed Social Worker
A state-licensed social worker.

See every abbreviation used in this directory →

Practice location Address checks out

435 W 4th St
Williamsport, PA 17701-6001
Phone: (570) 322-7873
Fax: (570) 322-8026
Show map & directions

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

Specialties & licences

Social Worker (primary) Taxonomy 104100000X · Licence SW124379 (PA)

Record details

NPI number1225078082
Entity typeIndividual (Type 1)
GenderMale
Credentials LSW
Sole proprietorNo
NPI enumeratedJune 8, 2006
Last updated in NPPESJuly 13, 2026
Mailing address10 Catherine Dr, Williamsport, PA 17701-1292

Other providers in Williamsport