Graham Mcmahon, M.D., M.M.SC.
NPI 1275512477 · Endocrinology, Diabetes & Metabolism Physician · Chicago, IL
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Graham Mcmahon, M.D., M.M.SC. is a Endocrinology, Diabetes & Metabolism Physician provider in Chicago, IL (NPI 1275512477).
Provider details
- NPI number
- 1275512477
- Entity type
- Individual
- Primary specialty
- Endocrinology, Diabetes & Metabolism PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D., M.M.SC.
- Sex
- Male
- Sole proprietor
- Yes
- License
- 205297 (MA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
20 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.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 3 distinct drugs on file.
| Drug | Part D claims (2024) |
|---|---|
| Tirzepatidebrand: Mounjaro | 15 |
| Dulaglutidebrand: Trulicity | 15 |
| Atorvastatin Calcium | 11 |
Medicare Part D only. These counts cover prescriptions paid through Medicare Part D in 2024 — they do notinclude cash-pay, commercial-insurance, Medicaid, or Part B–administered drugs, and badly undercount high cash-pay categories (e.g. GLP-1 weight-loss, testosterone, and ED medications). Any drug with 10 or fewer claims is omitted by CMS, and beneficiary counts under 11 are suppressed — so a missing drug means no Part D record, never zero. This is a factual claims summary, not an endorsement, not medical advice, and not a consumer report. Source: CMS Medicare Part D Prescribers — by Provider and Drug.
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-01-16
- Last updated
- 2021-07-23
- Certified
- 2021-07-23
Frequently asked questions
- What is Graham Mcmahon's NPI number?
- Graham Mcmahon's National Provider Identifier (NPI) is 1275512477, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Graham Mcmahon's specialty?
- Graham Mcmahon is listed in the NPPES registry with a primary specialty of Endocrinology, Diabetes & Metabolism Physician (Allopathic & Osteopathic Physicians).
- Where is Graham Mcmahon located?
- Graham Mcmahon's practice location on file with NPPES is 4025 N Sheridan Rd, Chicago, IL 60613.
- What is Graham Mcmahon's phone number?
- The practice phone number listed in the NPPES registry for Graham Mcmahon is (773) 388-1600.
- Does Graham Mcmahon accept Medicare?
- Graham Mcmahon is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Graham Mcmahon's NPI active?
- Yes — Graham Mcmahon's NPI (1275512477) is active in the NPPES registry as of the last update on 2021-07-23.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.