Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of August 10, 2026.
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Dr. Matilda Sylvia Mason, MD

Individual provider Internal Medicine Physician · NPI 1205141959

Dr. Matilda Sylvia Mason, MD practises Internal Medicine in Hackettstown, New Jersey. Qualified in 2002, 24 years ago. Practices with Practice Associates Medical Group, a 1,403-clinician group and accepts Medicare assignment. Licensed in New Jersey and New York.

Years since qualifying
24
Licensed in
NJ, NY
In the registry since
2010
Specialties on file
3
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

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Practice location Address checks out

651 Willow Grove St
Hackettstown, NJ 07840-1799
Phone: (908) 441-1161
Fax: (973) 383-4572
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Internal Medicine Physician (primary) Taxonomy 207R00000X · Licence 25MA09712200 (NJ)
Internal Medicine Physician Taxonomy 207R00000X · Licence 268687 (NY)
Student in an Organized Health Care Education/Training Program Taxonomy 390200000X

Record details

NPI number1205141959
Entity typeIndividual (Type 1)
GenderFemale
Credentials MD
Sole proprietorYes
NPI enumeratedAugust 18, 2010
Last updated in NPPESJuly 18, 2025
Certification dateJuly 18, 2025

Medicare enrollment

From the CMS Doctors & Clinicians file — this clinician is enrolled in Medicare.

Medicare specialtyINTERNAL MEDICINE
Medical schoolOTHER
Graduated 2002 (24 years in practice)
Group practice Practice Associates Medical Group — 1403 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
Practice locations3 on file with Medicare

Medicare patients and services, 2024

From the CMS Medicare Physician & Other Practitioners file for calendar year 2024. It counts Original Medicare patients only, so a practice that mostly sees Medicare Advantage or privately insured patients looks smaller here than it is.

Medicare patients377
Services billed 947 a service is one billed item, such as a visit, a test or a procedure
Average patient age78

Dollar amounts are not shown. What Medicare pays a practice is gross billings, before staff, premises and tax and including the cost of any drugs it administers, so it is not what a clinician earns.

Practises at

Facilities the CMS Facility Affiliation file lists for this clinician. Those with a page here are linked.

Colleagues at Practice Associates Medical Group

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 1403 clinicians in the practice; 12 are shown here.

Other providers in Hackettstown