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STEPHEN R. KNOWLTON PHD
NPI 1336291004
Psychologist - Clinical in Boston, MA

Active since January 16, 2007Opted out of Medicare · through Jan 1, 2027
466 COMMONWEALTH AVE, SUITE 201B, BOSTON, MA 02215(617) 859-5806 Get Directions Write a Review

NPPES record last updated: September 11, 2025. Verified against the NPPES registry weekly; last sync: August 02, 2026.

About Stephen R. Knowlton Phd NPPES

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

STEPHEN R. KNOWLTON PHD (NPI 1336291004) is an individual clinical provider in Boston, Massachusetts, licensed in Massachusetts (6510) and active in the NPI registry since January 2007. He has opted out of Medicare through January 1, 2027.

NPPES Registry Identity

NPI1336291004
Entity TypeIndividualMale
Primary Taxonomy103TC0700X
Provider Legal NameSTEPHEN R. KNOWLTONCredential: PHD
Location Address466 COMMONWEALTH AVE, SUITE 201BBoston, MA 02215-2721
Mailing Address466 Commonwealth Ave, Suite 201bBoston, MA 02215-2721 · (617) 859-5806
Phone(617) 859-5806
Sole ProprietorYes
Enumeration DateJanuary 16, 2007
Last NPPES UpdateSeptember 11, 2025
✔ NPI 1336291004 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtyPsychologist · ClinicalBehavioral Health & Social Service Providers
Taxonomy Code103TC0700X
License✔ Licensed in MA · 6510
Definition
A psychologist who provides continuing and comprehensive mental and behavioral health care for individuals and families; consultation to agencies and communities; training, education and supervision; and research-based practice. It is a specialty in breadth -- one that is broadly inclusive of severe psychopathology -- and marked by comprehensiveness and integration of knowledge and skill from a broad array of disciplines within and outside of psychology proper. The scope of clinical psychology encompasses all ages, multiple diversities and varied systems.
Also ListedPsychologistTaxonomy 103T00000X · License 6510 (MA)
466 COMMONWEALTH AVE, Boston, MA 02215
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Medicare Participation & PECOS CMS

Medicare enrollment, assignment, and ordering and referring status from the CMS PECOS system.

Medicare Enrollment Status

ⓘ

Opted out of Medicare

Stephen R. Knowlton Phd has filed a Medicare opt-out affidavit. Services are provided under private contract between the provider and the patient, and are not billed to or reimbursed by Medicare. The opt-out is on file from January 1, 2025 through January 1, 2027.

Opt-Out Effective DateJanuary 1, 2025
Opt-Out In Effect ThroughJanuary 1, 2027Opt-out affidavits renew automatically every two years unless cancelled

Other Providers at the Same Location NPPES 2

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

MS. JANE ELISABETH SCHERBAN LMHC
Counselor (Mental Health)
466 COMMONWEALTH AVE, SUITE 201B
BOSTON, MA 02215
Suffolk County (617) 859-5806
THE SHARON ST GROUP INC
Psychologist (Clinical)
466 COMMONWEALTH AVE, STE 201
BOSTON, MA 02215
Suffolk County (781) 856-4601

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 Stephen Knowlton's NPI number?

The NPI number for Stephen Knowlton is 1336291004. It was assigned to this individual provider in the NPPES registry on January 16, 2007.

Where is Stephen Knowlton located?

Stephen Knowlton practices at 466 Commonwealth Ave Suite 201B, Boston, MA 02215. The listed phone number is (617) 859-5806.

What is Stephen Knowlton's specialty?

The primary specialty registered for this NPI is Psychologist, specializing in Clinical, with taxonomy code 103TC0700X.

Is Stephen Knowlton enrolled in Medicare?

No. Stephen Knowlton has opted out of Medicare through January 1, 2027. Care is provided under private contracts, and Medicare does not pay for services furnished by providers who have opted out.

When was this NPI record last updated?

The NPPES record for Stephen Knowlton was last updated on September 11, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 10 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.