What is John Callahan's NPI number?

John Callahan's National Provider Identifier (NPI) is 1851704480, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.

What is John Callahan's specialty?

John Callahan is listed in the NPPES registry with a primary specialty of Pediatrics Physician (Allopathic & Osteopathic Physicians).

Where is John Callahan located?

John Callahan's practice location on file with NPPES is 1000 Langworthy St, Dubuque, IA 52001-7313.

What is John Callahan's phone number?

The practice phone number listed in the NPPES registry for John Callahan is (563) 584-3440.

Does John Callahan accept Medicare?

John Callahan is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.

Is John Callahan's NPI active?

Yes — John Callahan's NPI (1851704480) is active in the NPPES registry as of the last update on 2017-07-05.

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John Callahan, M.D.

NPI 1851704480 · Pediatrics Physician · Dubuque, IA

John Callahan, M.D. is a Pediatrics Physician provider in Dubuque, IA (NPI 1851704480).

Provider details

NPI number: 1851704480
Entity type: Individual
Primary specialty: Pediatrics PhysicianAllopathic & Osteopathic Physicians
Credential: M.D.
Sex: Male
Sole proprietor: No
License: MD-44274 (IA)

Practice location

1000 Langworthy St

Dubuque, IA 52001-7313

Phone: (563) 584-3440

Fax: (563) 584-3009

Street-level locationGet directions

More IA providers

Mailing address

1500 Associates Dr.

Dubuque, IA 52002-2201

Specialties & taxonomies

Pediatrics PhysicianPrimary208000000XLicense MD-44274 (IA)
Allopathic & Osteopathic Physicians

Enrolled with Medicare as Practitioner - Pediatric Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)

Profile Score

Detailed profile(76/100 index)

A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.

Registry tenure38% of score
12 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.

Enumerated: 2014-06-11
Last updated: 2017-07-05

Frequently asked questions

What is John Callahan's NPI number?: John Callahan's National Provider Identifier (NPI) is 1851704480, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
What is John Callahan's specialty?: John Callahan is listed in the NPPES registry with a primary specialty of Pediatrics Physician (Allopathic & Osteopathic Physicians).
Where is John Callahan located?: John Callahan's practice location on file with NPPES is 1000 Langworthy St, Dubuque, IA 52001-7313.
What is John Callahan's phone number?: The practice phone number listed in the NPPES registry for John Callahan is (563) 584-3440.
Does John Callahan accept Medicare?: John Callahan is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
Is John Callahan's NPI active?: Yes — John Callahan's NPI (1851704480) is active in the NPPES registry as of the last update on 2017-07-05.

Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.

Provider details

Practice location

Mailing address

Specialties & taxonomies

Profile Score

Registry dates

Frequently asked questions

Specialties & taxonomies

Profile Score

Frequently asked questions