Sean Mcmillan, M.D.
NPI 1558353821 · Rheumatology Physician · Twin Falls, ID
Enrolled with Medicare as Practitioner - Rheumatology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Sean Mcmillan, M.D. is a Rheumatology Physician provider in Twin Falls, ID (NPI 1558353821).
Provider details
- NPI number
- 1558353821
- Entity type
- Individual
- Primary specialty
- Rheumatology PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- 3571655 (ID)
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 tenure25% of score
20 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
2 documented practice locations
- Medicare service volume (vs. specialty peers)25% of score
766 Medicare services, 2024 (ranked within specialty)
- Open Payments transparency10% of score
Has Open Payments disclosures (2024)
Medicare volume is ranked against active providers in the same specialty. 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 .
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 384 | $93 |
| Visit Complexity Inherent to Evaluation and Management Associated With Medical Care Services That Serve As the Continuing Focal Point for All Needed Health Care Services And/Or With Medical Care Services That Are Part of Ongoing Care Related to a Patient'SG2211 | 352 | $16 |
| Established Patient Office Or Other Outpatient Visit With High Level of Medical Decision Making, If Using Time, 40 Minutes Or More99215 | 30 | $140 |
Typical Medicare-allowed amounts for these services range $16–$140 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, not a price quote and not what you would be billed. Medicare Part B covers roughly an eighth of all NPIs (65+ skew); services with fewer than 11 beneficiaries are suppressed by CMS. Source: CMS Medicare Physician & Other Practitioners, by Provider & Service.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 39 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Hydroxychloroquine Sulfate | 570 | 152 |
| Methotrexate Sodiumbrand: Methotrexate | 265 | 70 |
| Leflunomide | 206 | 52 |
| Prednisone | 193 | 54 |
| Folic Acid | 99 | 27 |
| Hydrocodone/Acetaminophenbrand: Hydrocodone-Acetaminophen | 80 | 12 |
| Alendronate Sodium | 79 |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$93 across 1 record (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Additional practice locations (1)
- 154 Myrtle AveSuite 204Murray, UT 84107-4833Phone: (801) 266-9300Fax: (801) 266-9305
Registry dates
- Enumerated
- 2005-08-22
- Last updated
- 2025-07-24
- Certified
- 2025-07-24
Frequently asked questions
- What is Sean Mcmillan's NPI number?
- Sean Mcmillan's National Provider Identifier (NPI) is 1558353821, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Sean Mcmillan's specialty?
- Sean Mcmillan is listed in the NPPES registry with a primary specialty of Rheumatology Physician (Allopathic & Osteopathic Physicians).
- Where is Sean Mcmillan located?
- Sean Mcmillan's practice location on file with NPPES is 801 Pole Line Rd W Ste 381, Twin Falls, ID 83301-5810.
- What is Sean Mcmillan's phone number?
- The practice phone number listed in the NPPES registry for Sean Mcmillan is (208) 814-8150.
- Does Sean Mcmillan accept Medicare?
- Sean Mcmillan is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Sean Mcmillan's NPI active?
- Yes — Sean Mcmillan's NPI (1558353821) is active in the NPPES registry as of the last update on 2025-07-24.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.