MARK JOHNSON MD
NPI 1780618694
Radiology - Nuclear Radiology in Southbury, CT

Q: What is Mark Johnson's NPI number?

The NPI number for Mark Johnson is 1780618694. It was assigned to this individual provider in the NPPES registry on July 10, 2006.

Q: What is Mark Johnson's specialty?

The primary specialty registered for this NPI is Radiology, specializing in Nuclear Radiology, with taxonomy code 2085N0904X.

Q: When was this NPI record last updated?

The NPPES record for Mark Johnson was last updated on September 11, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 10 months 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.

Active since July 10, 2006

385 MAIN ST SOUTH, UNION SQUARE, SOUTHBURY, CT 06488(203) 264-7999(203) 264-7477 Get Directions Write a Review

NPPES record last updated: September 11, 2025. Verified against the NPPES registry weekly; last sync: August 02, 2026.

On this page

About Mark Johnson Md NPPES

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

MARK JOHNSON MD (NPI 1780618694) is an individual nuclear radiology provider in Southbury, Connecticut, licensed in Connecticut (022134) and active in the NPI registry since July 2006.

NPPES Registry Identity

NPI1780618694

Entity TypeIndividualMale

Primary Taxonomy2085N0904X

Provider Legal NameMARK JOHNSONCredential: MD

Location Address385 MAIN ST SOUTH, UNION SQUARESouthbury, CT 06488

Mailing Address385 Main St South, Union Square Bldg #1Southbury, CT 06488 · (203) 264-7999 · Fax (203) 264-7477

Phone(203) 264-7999

Fax(203) 264-7477

Sole ProprietorNo

Enumeration DateJuly 10, 2006

Last NPPES UpdateSeptember 11, 2025

✔ NPI 1780618694 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 3

★ Primary SpecialtyRadiology · Nuclear RadiologyAllopathic & Osteopathic Physicians

Taxonomy Code2085N0904X

License✔ Licensed in CT · 022134

Definition

A radiologist who is involved in the analysis and imaging of radionuclides and radiolabeled substances in vitro and in vivo for diagnosis and the administration of radionuclides and radiolabeled substances for the treatment of disease.

Also ListedRadiology · Diagnostic RadiologyTaxonomy 2085R0202X · License 022134 (CT)

Also ListedRadiology · Diagnostic UltrasoundTaxonomy 2085U0001X · License 022134 (CT)

Medicare Quality Performance CMS QPP · MIPS

Performance in the CMS Quality Payment Program: the MIPS final score across four weighted categories, and the individual quality measures reported to Medicare.

Reported Quality Measures

Radiology: Stenosis Measurement in Carotid Imaging Reports

Percentage of final reports for carotid imaging studies (neck magnetic resonance angiography [MRA], neck computed tomography angiography [CTA], neck duplex ultrasound, carotid angiogram) performed that include direct or indirect reference to measurements of…

81%31 patients

Providers report different measures because they deliver different services; reporting more or less information is not a reflection of quality. Star ratings appear only where CMS assigned them.

Other Providers at the Same Location NPPES 9

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

MATTHEW BUSHEY MD

Radiology (Diagnostic Radiology)

385 MAIN ST SOUTH, UNION SQUARE
SOUTHBURY, CT 06488

Naugatuck Valley Planning Region (203) 264-7999

GINA RUPERT PAC

Physician Assistant (Medical)

385 MAIN ST SOUTH, STE 301 UNION SQUARE
SOUTHBURY, CT 06488

Naugatuck Valley Planning Region (203) 264-3319

DIAGNOSTIC IMAGING OF SOUTHBURY

Clinic/Center (Radiology)

385 MAIN ST SOUTH, NVRA UNION SQUARE BLDG 2
SOUTHBURY, CT 06488

Naugatuck Valley Planning Region (203) 264-7999

ROBERT GUMBARDO MD

Radiology (Nuclear Radiology)

385 MAIN ST SOUTH, UNION SQUARE
SOUTHBURY, CT 06488

Naugatuck Valley Planning Region (203) 264-7999

GEOFFREY L MANTON MD

Radiology (Diagnostic Radiology)

385 MAIN ST SOUTH, UNION SQUARE
SOUTHBURY, CT 06488

Naugatuck Valley Planning Region (203) 264-7999

PHILIP ROTHFELD MD

Radiology (Diagnostic Radiology)

385 MAIN ST SOUTH, UNION SQUARE, BLDG#1
SOUTHBURY, CT 06488

Naugatuck Valley Planning Region (203) 264-7999

BIPINCHANDRA JAGJIVAN

Radiology (Diagnostic Radiology)

385 MAIN ST SOUTH, UNION SQUARE BLDG #1 NVRA IMAGING NETWORK
SOUTHBURY, CT 06488

Naugatuck Valley Planning Region (203) 264-7999

CAROLYN AJEMIAN MD

Radiology (Diagnostic Radiology)

385 MAIN ST SOUTH, UNION SQUARE
SOUTHBURY, CT 06488

Naugatuck Valley Planning Region (203) 264-7999

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 Mark Johnson's NPI number?

The NPI number for Mark Johnson is 1780618694. It was assigned to this individual provider in the NPPES registry on July 10, 2006.

Where is Mark Johnson located?

Mark Johnson practices at 385 Main St South Union Square, Southbury, CT 06488. The listed phone number is (203) 264-7999.

What is Mark Johnson's specialty?

The primary specialty registered for this NPI is Radiology, specializing in Nuclear Radiology, with taxonomy code 2085N0904X.

When was this NPI record last updated?

The NPPES record for Mark Johnson was last updated on September 11, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 10 months 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.