Karen Janet Terwilliger, MS, APRN, AGPCNP-BC
Gerontology Nurse Practitioner · Mystic, CT
Karen Janet Terwilliger, MS, APRN, AGPCNP-BC is a gerontology nurse practitioner with a practice address in Mystic, Connecticut, and NPI 1245616705, issued on Aug 7, 2015. Check the license (Connecticut 6220, as entered in NPPES) with the Connecticut board that licenses this profession; the Medicare figures below come from public CMS files.
- Name
- Karen Janet Terwilliger
- Credential
- MS, APRN, AGPCNP-BC
- Primary taxonomy
- Gerontology Nurse Practitioner 363LG0600X
- License number
- 6220 CT
Self-reported in NPPES; status is on the state search - Practice location
- 3 Heron RD, Mystic, CT 06355
- Phone
- (401) 497-6799
- Enumerated
- Aug 7, 2015
- Record last updated
- Jun 2, 2026
- Entity
- Type 1 · individual
8 nearest gerontology nurse practitioner records → All 166 in Connecticut → Look up another NPI →
Also registered at 3 Heron RD
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Michael Feltes, M.D.Family Medicine Physician1689690216
- Mary Ellen Pagnozzi, A.P.R.N.Adult Health Nurse Practitioner1114943214
- Harold Phillips, M.D.Family Medicine Physician1124026869
- Cheryl Walker, APRNGerontology Nurse Practitioner1730182353
Verify Karen Janet Terwilliger in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersWhich Connecticut board licenses this profession
Search for license 6220Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
96% fewer Medicare Part D claims than the average gerontology nurse practitioner in 2024
56 Medicare Part D claims for 20 beneficiaries, against an average of 1,369 among the 6,165 providers of this specialty who prescribed in Part D.
Most prescribed
- Santyl11 claims
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
Karen Janet Terwilliger among 166 gerontology nurse practitioner records in Connecticut
Karen Janet Terwilliger, MS, APRN, AGPCNP-BC is one of 166 gerontology nurse practitioner records with a practice address in Connecticut. 75% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2015, is newer than 33% of them.
- NPI issued2015 · 33% of these records are older, 64% newer
- In a Medicare fileYes · 75% of these records are
- In the CMS Doctors and Clinicians fileNo · 63% of these records are
- Record last updated2026 · 40% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 363LG0600X and a Connecticut practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
3 gerontology nurse practitioner records list a practice address in Mystic
They are 3 of the 242 NPPES records with a practice address in Mystic, and 166 gerontology nurse practitioner records in Connecticut.
All 166 in Connecticut → Every provider in Mystic → Gerontology Nurse Practitioner nationwide →
The 8 gerontology nurse practitioner records with the nearest ZIP codes
- Elena Schjavland, APRNMystic, CT 063551871689679
- Cheryl Walker, APRNMystic, CT 063551730182353
- Jeanne Harrington, AGNP-CNorwich, CT 063601194452599
- Ryan MansiNorwich, CT 063601558986174
- Danielle Sorano, APRNNorwich, CT 063601144995424
- Kayla St AmourNorwich, CT 063601205330610
- Kelly Klein, N.P.Groton, CT 063491861828832
- Gabriell Budoff, AGNP-COld Lyme, CT 063711265911473
Common questions
What is Karen Janet Terwilliger, MS, APRN, AGPCNP-BC's NPI number?
Karen Janet Terwilliger, MS, APRN, AGPCNP-BC's National Provider Identifier (NPI) is 1245616705, issued on Aug 7, 2015. An NPI identifies a provider in billing; it is not a license.
Where is Karen Janet Terwilliger, MS, APRN, AGPCNP-BC located?
The NPPES record lists a practice address at 3 Heron RD, Mystic, CT, 06355. Phone: (401) 497-6799. Providers update this record themselves, so call before visiting.
How can I verify Karen Janet Terwilliger, MS, APRN, AGPCNP-BC's license?
NPPES lists Connecticut license number 6220, as entered by the provider. Search the Connecticut board that licenses this profession; the NPPES record confirms identity only.
How much does Karen Janet Terwilliger, MS, APRN, AGPCNP-BC prescribe under Medicare Part D?
In 2024, Karen Janet Terwilliger, MS, APRN, AGPCNP-BC had 56 Medicare Part D claims for 20 beneficiaries; the average among gerontology nurse practitioner prescribers was 1,369. Part D covers Medicare prescriptions only.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.