William Mark, M.D.
NPI 1396955522 · Internal Medicine Physician · Phoenixville, PA
William Mark, M.D. is a Internal Medicine Physician provider in Phoenixville, PA (NPI 1396955522).
Provider details
- NPI number
- 1396955522
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- Yes
- License
- 012108E (PA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
19 yrs in NPPES registry
- Profile completeness38% of score
100% of core fields populated
- Practice footprint23% of score
1 documented practice location
Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
Practice location
Mailing address
Registry dates
- Enumerated
- 2007-05-23
- Last updated
- 2007-07-08
Frequently asked questions
- What is William Mark's NPI number?
- William Mark's National Provider Identifier (NPI) is 1396955522, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Mark's specialty?
- William Mark is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is William Mark located?
- William Mark's practice location on file with NPPES is 143 Church St, Phoenixville, PA 19460-3438.
- What is William Mark's phone number?
- The practice phone number listed in the NPPES registry for William Mark is (610) 935-1134.
- Is William Mark's NPI active?
- Yes — William Mark's NPI (1396955522) is active in the NPPES registry as of the last update on 2007-07-08.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.