Mark Johnson, MD
NPI 1780618694 · Nuclear Radiology Physician · Southbury, CT
Mark Johnson, MD is a Nuclear Radiology Physician provider in Southbury, CT (NPI 1780618694).
Provider details
- NPI number
- 1780618694
- Entity type
- Individual
- Primary specialty
- Nuclear Radiology PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- 022134 (CT)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
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
- 2006-07-10
- Last updated
- 2025-09-11
Frequently asked questions
- What is Mark Johnson's NPI number?
- Mark Johnson's National Provider Identifier (NPI) is 1780618694, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Mark Johnson's specialty?
- Mark Johnson is listed in the NPPES registry with a primary specialty of Nuclear Radiology Physician (Allopathic & Osteopathic Physicians).
- Where is Mark Johnson located?
- Mark Johnson's practice location on file with NPPES is 385 Main St South, Southbury, CT 06488.
- What is Mark Johnson's phone number?
- The practice phone number listed in the NPPES registry for Mark Johnson is (203) 264-7999.
- Is Mark Johnson's NPI active?
- Yes — Mark Johnson's NPI (1780618694) is active in the NPPES registry as of the last update on 2025-09-11.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.