NPI Portal NPI Lookup & Verification

Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

William R Closs III, LAT, ATC, CSCS

Athletic Trainer in Nashua, NH · enumerated 2024 · practices at Gate City Sports Medicine.

Data current as of Jul 13, 2026 · sourced from CMS NPPES

National Provider Identifier

1386484582

Verified

See something wrong? Report a correction

Registry record

Entity type Individual (Type 1)
Name William R Closs III
Credential LAT, ATC, CSCS
Sex Male
Practice address 436 Amherst St Ste 102, Nashua, NH, 03063
Phone (603) 417-5087
Fax (603) 417-5089
Enumeration date May 28, 2024
Last updated in NPPES May 28, 2024

Taxonomy & licenses

2255A2300X Athletic Trainer Respiratory, Developmental, Rehabilitative and Restorative Service Providers · License ATL3290 (MA) Secondary
2255A2300X Athletic Trainer Respiratory, Developmental, Rehabilitative and Restorative Service Providers · License 0396 (NH) Primary

What is an NPI number?

A National Provider Identifier (NPI) is a unique 10-digit number that CMS assigns to every U.S. healthcare provider and organization under HIPAA. Type 1 NPIs identify individual providers; Type 2 NPIs identify organizations. The NPI appears on insurance claims, prescriptions, and credentialing paperwork, and never changes, even if the provider moves or changes specialty.

Read the full guide → Validate an NPI →

Frequently asked questions

What is the NPI number for William Closs?
The National Provider Identifier (NPI) for William Closs is 1386484582, a Type 1 (individual) record in the CMS NPPES registry.
Where does William Closs practice?
The practice location on file with NPPES is in Nashua, NH. Providers can have multiple locations; NPPES lists the primary practice address.

Other providers at this practice address

Browse all →

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2024-05-28.