John Mcmahan, MD
John Mcmahan, MD is an Otolaryngology Physician in Appleton, WI, registered under NPI 1518910272. This provider registers 2 separate taxonomy codes, which usually means they practise across more than one recognised specialty.
Getting there
The practice address on file is 247 S NICOLET RD, Appleton, WI 54914. We have not yet mapped what surrounds this office — parking, transit, and nearby pharmacies are added as our data collection reaches each location.
Credentials and Medicare
| Licence | State | Specialty |
|---|---|---|
| 036051277 | IL | Otolaryngic Allergy Physician |
| 036051277 | IL | Otolaryngology Physician primary |
This provider holds licence 036051277 issued in IL. A licence number in NPPES reflects what was filed at registration — it does not confirm the licence is still active today.
- Status
- Approved
- Provider type
- Practitioner - Otolaryngology
- PAC ID
- 5991789133
Enrolled in Medicare 6 times, across 6 states:
| State | Enrollment ID | Provider type |
|---|---|---|
| Illinois | I20040616000382 | Practitioner - Otolaryngology |
| California | I20191022001841 | Practitioner - Otolaryngology |
| Maine | I20210226000209 | Practitioner - Otolaryngology |
| Florida | I20220127002538 | Practitioner - Otolaryngology |
| Texas | I20240620004131 | Practitioner - Otolaryngology |
| Wisconsin | I20250416002420 | Practitioner - Otolaryngology |
Medicare enrolment is recorded as approved under the provider type Practitioner - Otolaryngology. There are 6 separate enrolment records across 6 states (IL, CA, ME, FL, TX, WI). Multiple enrolments usually mean the provider bills Medicare from more than one practice location, or has kept an earlier enrolment after moving. Each record carries its own enrolment ID, listed above. Being enrolled means the provider can bill Medicare; it does not tell you whether they are currently accepting new Medicare patients. Call the office to confirm.
What Otolaryngology covers
An otolaryngologist-head and neck surgeon provides comprehensive medical and surgical care for patients with diseases and disorders that affect the ears, nose, throat, the respiratory and upper alimentary systems and related structures of the head and neck. An otolaryngologist diagnoses and provides medical and/or surgical therapy or prevention of diseases, allergies, neoplasms, deformities, disorders and/or injuries of the ears, nose, sinuses, throat, respiratory and upper alimentary systems, face, jaws and the other head and neck systems. Head and neck oncology, facial plastic and reconstructive surgery and the treatment of disorders of hearing and voice are fundamental areas of expertise. NUCC Health Care Provider Taxonomy, code 207Y00000X
All registered taxonomy codes
This provider registers 2 taxonomy codes. The primary code is what appears on most claims; the others record additional recognised specialties.
| Code | Specialty | Licence | State | |
|---|---|---|---|---|
| 207YX0602X | Otolaryngic Allergy Physician Otolaryngic Allergy | 036051277 | IL | |
| 207Y00000X | Otolaryngology Physician | 036051277 | IL | primary |
The taxonomy records how the provider classifies their own practice. It does not confirm which conditions they currently treat, whether they are accepting new patients, or which insurance they take — call the office for that.
Full NPPES record
An NPI-1 identifies a single person. It stays with the clinician for life, even if they move practice or change state, which is why the address on file can lag behind where they actually work today.
| NPI | 1518910272 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | May 17, 2006 |
| Last updated | Apr 1, 2025 |
| Status | Active |
| Sole proprietor | No |
| Gender | Male |
| Credential | MD |
| Practice address |
247 S NICOLET RD Appleton, WI 54914 (888) 938-3838 Fax (888) 919-1083 |
| Mailing address |
10001 W INNOVATION DR STE 200 Milwaukee, WI 53226 |
| Other identifiers |
036051277
· Medicaid (IL) |
Number check
How the check works, step by step
Every NPI carries a Luhn check digit — the same scheme used on credit cards. CMS prefixes the number with 80840 before computing it, which marks it as a US health identifier.
| Digit | 8 | 0 | 8 | 4 | 0 | 1 | 5 | 1 | 8 | 9 | 1 | 0 | 2 | 7 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 5 | 2 | 8 | 9 | 1 | 0 | 2 | 5 |
Sum = 58 · next multiple of 10 = 60 · check digit = 2 · actual last digit = 2
A valid check digit only means the number is well-formed. It does not mean the provider is licensed, active, or in good standing — those are separate questions answered by the sections above.