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DR. WILLIAM STEVEN MARK M.D.
NPI 1396955522
Internal Medicine in Phoenixville, PA

Active since May 23, 2007
143 CHURCH ST, PHOENIXVILLE, PA 19460(610) 935-1134(610) 935-8191 Get Directions Write a Review

NPPES record last updated: July 8, 2007. Verified against the NPPES registry weekly; last sync: August 16, 2026.

About Dr. William Steven Mark M.d. NPPES

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

DR. WILLIAM STEVEN MARK M.D. (NPI 1396955522) is an individual internal medicine provider in Phoenixville, Pennsylvania, licensed in Pennsylvania (012108E) and active in the NPI registry since May 2007.

NPPES Registry Identity

NPI1396955522
Entity TypeIndividualMale
Primary Taxonomy207R00000X
Provider Legal NameDR. WILLIAM STEVEN MARKCredential: M.D.
Location Address143 CHURCH STPhoenixville, PA 19460-3438
Mailing Address26 Salem WayMalvern, PA 19355-9705 · (610) 296-2506 · Fax (610) 647-5133
Phone(610) 935-1134
Fax(610) 935-8191
Sole ProprietorYes
Enumeration DateMay 23, 2007
Last NPPES UpdateJuly 8, 2007
✔ NPI 1396955522 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal MedicineAllopathic & Osteopathic Physicians
Taxonomy Code207R00000X
License✔ Licensed in PA · 012108E
Definition
A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults and the elderly. Internists are trained in the diagnosis and treatment of cancer, infections and diseases affecting the heart, blood, kidneys, joints and digestive, respiratory and vascular systems. They are also trained in the essentials of primary care internal medicine, which incorporates an understanding of disease prevention, wellness, substance abuse, mental health and effective treatment of common problems of the eyes, ears, skin, nervous system and reproductive organs.
143 CHURCH ST, Phoenixville, PA 19460
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Other Identifiers 2

Medicare ID-Type UnspecifiedMA125287PA
Medicare UPIND70030PA

Other Providers at the Same Location NPPES 6

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

JACLYN ARIEL TULLY CRNP
Nurse Practitioner (Adult Health)
143 CHURCH ST
PHOENIXVILLE, PA 19460
Chester County (610) 935-1134
ANA BERTA SANTOYO LCSW
Social Worker (Clinical)
143 CHURCH ST
PHOENIXVILLE, PA 19460
Chester County (610) 518-4939
DR. JEFFREY S ROMEO M.D.
Internal Medicine
143 CHURCH ST
PHOENIXVILLE, PA 19460
Chester County (610) 935-1134
DR. SUSAN HOWE PROUTY M.D.
Internal Medicine
143 CHURCH ST
PHOENIXVILLE, PA 19460
Chester County (610) 935-1134
DR. ERIC STEPHEN HOLMBOE M.D.
Internal Medicine
143 CHURCH ST
PHOENIXVILLE, PA 19460
Chester County (610) 935-1134
ANDREA W PELLEGRINO MD
Family Medicine
143 CHURCH ST
PHOENIXVILLE, PA 19460
Chester County (610) 935-1134

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 Mark's NPI number?

The NPI number for William Mark is 1396955522. It was assigned to this individual provider in the NPPES registry on May 23, 2007.

Where is William Mark located?

William Mark practices at 143 Church St, Phoenixville, PA 19460. The listed phone number is (610) 935-1134.

What is William Mark's specialty?

The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.

When was this NPI record last updated?

The NPPES record for William Mark was last updated on July 8, 2007. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 19 years 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.