William Nelson, MD
NPI 1326051640 · Internal Medicine Physician · Elgin, IL
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
William Nelson, MD is a Internal Medicine Physician provider in Elgin, IL (NPI 1326051640).
Provider details
- NPI number
- 1326051640
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- 036091028 (IL)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
19 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)28% of score
636 Medicare services, 2024 (ranked within specialty)
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 methodology.
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 | 312 | $132 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 176 | $93 |
| Annual Wellness Visit, Includes a Personalized Prevention Plan of Service (pps), Subsequent VisitG0439 | 95 | $133 |
| Established Patient Office Or Other Outpatient Visit With High Level of Medical Decision Making, If Using Time, 40 Minutes Or More99215 | 53 | $185 |
Typical Medicare-allowed amounts for these services range $93–$185 (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 · 75 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Atorvastatin Calcium | 166 | 42 |
| Amlodipine Besylate | 108 | 29 |
| Levothyroxine Sodium | 97 | 26 |
| Metformin Hcl | 95 | 28 |
| Simvastatin | 89 | 23 |
| Alprazolam | 87 | 15 |
| Omeprazole | 83 |
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-08-15
- Last updated
- 2012-09-28
Frequently asked questions
- What is William Nelson's NPI number?
- William Nelson's National Provider Identifier (NPI) is 1326051640, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Nelson's specialty?
- William Nelson is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is William Nelson located?
- William Nelson's practice location on file with NPPES is 87 North Airlite, Elgin, IL 60123.
- What is William Nelson's phone number?
- The practice phone number listed in the NPPES registry for William Nelson is (847) 697-5144.
- Does William Nelson accept Medicare?
- William Nelson is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is William Nelson's NPI active?
- Yes — William Nelson's NPI (1326051640) is active in the NPPES registry as of the last update on 2012-09-28.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.