Leo Xavier Callahan, M.D.
NPI 1598955627 · Otolaryngology Physician · East Boston, MA
Leo Xavier Callahan, M.D. is a Otolaryngology Physician provider in East Boston, MA (NPI 1598955627).
Provider details
- NPI number
- 1598955627
- Entity type
- Individual
- Primary specialty
- Otolaryngology PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- 58717 (MA)
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
18 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
- 2007-07-25
- Last updated
- 2007-07-25
Frequently asked questions
- What is Leo Xavier Callahan's NPI number?
- Leo Xavier Callahan's National Provider Identifier (NPI) is 1598955627, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Leo Xavier Callahan's specialty?
- Leo Xavier Callahan is listed in the NPPES registry with a primary specialty of Otolaryngology Physician (Allopathic & Osteopathic Physicians).
- Where is Leo Xavier Callahan located?
- Leo Xavier Callahan's practice location on file with NPPES is 79 Meridian St, East Boston, MA 02128-1959.
- What is Leo Xavier Callahan's phone number?
- The practice phone number listed in the NPPES registry for Leo Xavier Callahan is (617) 407-7568.
- Is Leo Xavier Callahan's NPI active?
- Yes — Leo Xavier Callahan's NPI (1598955627) is active in the NPPES registry as of the last update on 2007-07-25.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.