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WILLIAM THORNTON PMHNP
NPI 1225842065
Nurse Practitioner - Psychiatric/Mental Health in Somerville, MA

Active since February 03, 2025PECOS EnrolledAccepts Medicare Assignment
165 HUDSON ST APT 1, SOMERVILLE, MA 02144(610) 291-1489 Get Directions Write a Review

NPPES record last updated: August 26, 2025. Verified against the NPPES registry weekly; last sync: October 18, 2026.

About William Thornton Pmhnp NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

WILLIAM THORNTON PMHNP (NPI 1225842065) is an individual psychiatric/mental health provider in Somerville, Massachusetts, licensed in Massachusetts (RN2352821) and active in the NPI registry since February 2025. He is enrolled in Medicare PECOS and is a graduate of Other (2023).

NPPES Registry Identity

NPI1225842065
Entity TypeIndividualMale
Primary Taxonomy363LP0808X
Provider Legal NameWILLIAM THORNTONCredential: PMHNP
Location Address165 HUDSON ST APT 1Somerville, MA 02144-2631
Mailing Address17 Research DrAmherst, MA 01002-2788 · (413) 549-8400 · Fax (413) 549-8409
Phone(610) 291-1489
Sole ProprietorYes
Medical School CMSOtherGraduated 2023
Enumeration DateFebruary 3, 2025
Last NPPES UpdateAugust 26, 2025
NPPES CertifiedAugust 26, 2025
✔ NPI 1225842065 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtyNurse Practitioner · Psychiatric/Mental HealthPhysician Assistants & Advanced Practice Nursing Providers
Taxonomy Code363LP0808X
License✔ Licensed in MA · RN2352821
Also ListedRegistered NurseTaxonomy 163W00000X · License RN2352821 (MA)
165 HUDSON ST APT 1, Somerville, MA 02144
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Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Harvard Pilgrim Health Care.Insurance ›

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

William Thornton Pmhnp is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.

PECOS PAC ID6002312949
PECOS Enrollment IDI20250930004214
Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Medicare Billing Reassignment

Medicare enrollment records show William Thornton reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.

Katherine J. Atkinson, MD, PC
70 mi
Internal Medicine
17 RESEARCH DR
Amherst, MA 01002
  • Reassigned Medicare billing, Massachusetts enrollment
  • 14 clinicians in this Medicare group
NPI 1568598993 (413) 549-8400

Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 02144 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient
$97.64 typical visit price
range $63.72 – $189.86
Typical copayment $24.41 (range $15.93 – $47.46)
Most-billed visit code 99203
Established Patient
$111.18 typical visit price
range $21.07 – $155.29
Typical copayment $27.79 (range $5.26 – $38.82)
Most-billed visit code 99214
Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is William Thornton's NPI number?

The NPI number for William Thornton is 1225842065. It was assigned to this individual provider in the NPPES registry on February 3, 2025.

Where is William Thornton located?

William Thornton practices at 165 Hudson St Apt 1, Somerville, MA 02144. The listed phone number is (610) 291-1489.

What is William Thornton's specialty?

The primary specialty registered for this NPI is Nurse Practitioner, specializing in Psychiatric/Mental Health, with taxonomy code 363LP0808X.

Is William Thornton enrolled in Medicare?

Yes. William Thornton is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.

Which organization bills Medicare for William Thornton's services?

According to the CMS Revalidation Reassignment List (October 2026 release), William Thornton reassigns Medicare benefits to Katherine J. Atkinson, MD, PC (Amherst, MA). The reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for William Thornton's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

What insurance does William Thornton accept?

Health plans from Harvard Pilgrim Health Care list William Thornton as in-network in at least one marketplace plan. Coverage varies by plan and year; verify with the insurer or the provider before a visit.

When was this NPI record last updated?

The NPPES record for William Thornton was last updated on August 26, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 13 months ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.