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Recently Updated NPI Information — some details in this NPI profile have been updated in the NPI registry within the last 60 days.

CATHY SIZER NP
NPI 1467449512
Nurse Practitioner - Pediatrics in Westford, MA

Active since October 04, 2005
133 LITTLETON RD, SUITE 101, WESTFORD, MA 01886(978) 577-0437(978) 692-9904 Get Directions Write a Review

NPPES record last updated: July 13, 2026. Verified against the NPPES registry weekly; last sync: August 09, 2026.

About Cathy Sizer Np NPPES

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

CATHY SIZER NP (NPI 1467449512) is an individual pediatrics provider in Westford, Massachusetts, licensed in Massachusetts (153270) and active in the NPI registry since October 2005.

NPPES Registry Identity

NPI1467449512
Entity TypeIndividualFemale
Primary Taxonomy363LP0200X
Provider Legal NameCATHY SIZERCredential: NP
Location Address133 LITTLETON RD, SUITE 101Westford, MA 01886-3198
Mailing Address346 Bacon StWaltham, MA 02451-7516
Phone(978) 577-0437
Fax(978) 692-9904
Sole ProprietorNo
Enumeration DateOctober 4, 2005
Last NPPES UpdateJuly 13, 2026
✔ NPI 1467449512 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyNurse Practitioner · PediatricsPhysician Assistants & Advanced Practice Nursing Providers
Taxonomy Code363LP0200X
License✔ Licensed in MA · 153270
133 LITTLETON RD, Westford, MA 01886
Open in Google Maps ↗

Other Providers at the Same Location NPPES 20

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

JAMES P COHEN M.D.
Internal Medicine
133 LITTLETON RD, SUITE 202
WESTFORD, MA 01886
Middlesex County (978) 577-1946
LYNN EARLY RUSHTON N.P.
Internal Medicine
133 LITTLETON RD, SUITE 202
WESTFORD, MA 01886
Middlesex County (978) 589-6700
SEEMA AZAM M.D.
Internal Medicine
133 LITTLETON RD, SUITE 202
WESTFORD, MA 01886
Middlesex County (978) 577-1946
JUDITH LAPPING KREMNICK N.P.
Internal Medicine
133 LITTLETON RD, SUITE 202
WESTFORD, MA 01886
Middlesex County (978) 589-6700
JOAN EAGAN MD, FAAP
Pediatrics
133 LITTLETON RD, SUITE 101
WESTFORD, MA 01886
Middlesex County (978) 577-0437
MRS. TRICIA E FULLER N.P.
Nurse Practitioner (Adult Health)
133 LITTLETON RD, SUITE 202
WESTFORD, MA 01886
Middlesex County (978) 589-6700
MICHELLE SANDERS MD
Pediatrics
133 LITTLETON RD, SUITE 101
WESTFORD, MA 01886
Middlesex County (978) 577-0437
KATHERINE L PHANEUF MD
Internal Medicine
133 LITTLETON RD, SUITE 202
WESTFORD, MA 01886
Middlesex County (978) 577-1946

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 Cathy Sizer's NPI number?

The NPI number for Cathy Sizer is 1467449512. It was assigned to this individual provider in the NPPES registry on October 4, 2005.

Where is Cathy Sizer located?

Cathy Sizer practices at 133 Littleton Rd Suite 101, Westford, MA 01886. The listed phone number is (978) 577-0437.

What is Cathy Sizer's specialty?

The primary specialty registered for this NPI is Nurse Practitioner, specializing in Pediatrics, with taxonomy code 363LP0200X.

When was this NPI record last updated?

The NPPES record for Cathy Sizer was last updated on July 13, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 31 days 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.