Karen Terwilliger, MS, APRN, AGPCNP-BC
NPI 1245616705 · Gerontology Nurse Practitioner · Mystic, CT
Enrolled with Medicare as Practitioner - Nurse Practitioner · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Karen Terwilliger, MS, APRN, AGPCNP-BC is a Gerontology Nurse Practitioner provider in Mystic, CT (NPI 1245616705).
Provider details
- NPI number
- 1245616705
- Entity type
- Individual
- Primary specialty
- Gerontology Nurse PractitionerPhysician Assistants & Advanced Practice Nursing Providers
- Credential
- MS, APRN, AGPCNP-BC
- Sex
- Female
- Sole proprietor
- No
- License
- 6220 (CT)
Specialties & taxonomies
Physician Assistants & Advanced Practice Nursing Providers
Physician Assistants & Advanced Practice Nursing Providers
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
10 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
3 documented practice locations
- Medicare service volume (vs. specialty peers)28% of score
993 Medicare services, 2024 (ranked within specialty)
Medicare volume is ranked against active providers in the same specialty. Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Subsequent Nursing Facility Care With Straightforward Level of Medical Decision Making, Per Day, If Using Time, 20 Minutes Or More99308 | 451 | $65 |
| Subsequent Nursing Facility Care With Straightforward Level of Medical Decision Making, Per Day, If Using Time, at Least 10 Minutes99307 | 191 | $35 |
| Subsequent Nursing Facility Care With Moderate Level of Medical Decision Making, Per Day, If Using Time, at Least 30 Minutes99309 | 85 | $94 |
| Residence Visit for Established Patient With Moderate Level of Medical Decision Making, Per Day, If Using Time, at Least 40 Minutes99349 | 70 | $110 |
| Removal of Skin and Tissue, 20.0 Sq Cm Or Less11042 | 62 | $117 |
| Residence Visit for Established Patient With Low Level of Medical Decision Making, Per Day, If Using Time, at Least 30 Minutes |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024.
| Drug | Part D claims (2024) |
|---|---|
| Collagenase Clostridium Hist.brand: Santyl | 11 |
Medicare Part D only. These counts cover prescriptions paid through Medicare Part D in 2024 — they do notinclude cash-pay, commercial-insurance, Medicaid, or Part B–administered drugs, and badly undercount high cash-pay categories (e.g. GLP-1 weight-loss, testosterone, and ED medications). Any drug with 10 or fewer claims is omitted by CMS, and beneficiary counts under 11 are suppressed — so a missing drug means no Part D record, never zero. This is a factual claims summary, not an endorsement, not medical advice, and not a consumer report. Source: CMS Medicare Part D Prescribers — by Provider and Drug.
Practice location
Mailing address
Additional practice locations (2)
- 111 Salem TpkeNorwich, CT 06360-7403Phone: (860) 425-8700
- 112 Mansfield AveWillimantic, CT 06226-2045Phone: (860) 456-6965
Registry dates
- Enumerated
- 2015-08-07
- Last updated
- 2026-06-02
- Certified
- 2026-06-02
Frequently asked questions
- What is Karen Terwilliger's NPI number?
- Karen Terwilliger's National Provider Identifier (NPI) is 1245616705, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Karen Terwilliger's specialty?
- Karen Terwilliger is listed in the NPPES registry with a primary specialty of Gerontology Nurse Practitioner (Physician Assistants & Advanced Practice Nursing Providers).
- Where is Karen Terwilliger located?
- Karen Terwilliger's practice location on file with NPPES is 3 Heron Rd, Mystic, CT 06355-3253.
- What is Karen Terwilliger's phone number?
- The practice phone number listed in the NPPES registry for Karen Terwilliger is (401) 497-6799.
- Does Karen Terwilliger accept Medicare?
- Karen Terwilliger is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Karen Terwilliger's NPI active?
- Yes — Karen Terwilliger's NPI (1245616705) is active in the NPPES registry as of the last update on 2026-06-02.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.