Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of October 4, 2026.
NPIDirectory

Mrs. Karen Janet Terwilliger, MS, APRN, AGPCNP-BC

Individual provider Gerontology Nurse Practitioner · NPI 1245616705

Mrs. Karen Janet Terwilliger, MS, APRN, AGPCNP-BC is a Gerontology Nurse Practitioner in Mystic, Connecticut. Works from 3 locations. Licensed in Connecticut.

Licensed in
CT
In the registry since
2015
Specialties on file
2
What do these letters mean?
MS — Master of Science
A graduate science degree.
APRN — Advanced Practice Registered Nurse
The umbrella licence covering nurse practitioners, midwives, anaesthetists and clinical nurse specialists.

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Practice location Address checks out

3 Heron Rd
Mystic, CT 06355-3253
Phone: (401) 497-6799
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Additional practice locations (2)

  • 111 Salem Tpke, Norwich, CT 06360-7403 — (860) 425-8700
  • 112 Mansfield Ave, Willimantic, CT 06226-2045 — (860) 456-6965

Specialties & licences

Gerontology Nurse Practitioner (primary) Taxonomy 363LG0600X · Licence 6220 (CT)
Primary Care Nurse Practitioner Taxonomy 363LP2300X · Licence 6220 (CT)

Record details

NPI number1245616705
Entity typeIndividual (Type 1)
GenderFemale
Credentials MS , APRN , AGPCNP-BC
Sole proprietorNo
NPI enumeratedAugust 7, 2015
Last updated in NPPESJune 2, 2026
Certification dateJune 2, 2026

Medicare patients and services, 2024

From the CMS Medicare Physician & Other Practitioners file for calendar year 2024. It counts Original Medicare patients only, so a practice that mostly sees Medicare Advantage or privately insured patients looks smaller here than it is.

Medicare patients157
Services billed 1,030 a service is one billed item, such as a visit, a test or a procedure
Average patient age77

Dollar amounts are not shown. What Medicare pays a practice is gross billings, before staff, premises and tax and including the cost of any drugs it administers, so it is not what a clinician earns.

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