William Leslie, M.D.
NPI 1538129275 · Hematology & Oncology Physician · Chicago, IL
Enrolled with Medicare as Practitioner - Hematology/Oncology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
William Leslie, M.D. is a Hematology & Oncology Physician provider in Chicago, IL (NPI 1538129275).
Provider details
- NPI number
- 1538129275
- Entity type
- Individual
- Primary specialty
- Hematology & Oncology PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- 036-058921 (IL)
Specialties & taxonomies
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
1 documented practice location
- Medicare service volume (vs. specialty peers)25% of score
736 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 High Level of Medical Decision Making, If Using Time, 40 Minutes Or More99215 | 374 | $148 |
| Established Patient Office Or Other Outpatient Visit With High Level of Medical Decision Making, If Using Time, 40 Minutes Or More99215 | 270 | $149 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 25 | $100 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 22 | $100 |
| New Patient Office Or Other Outpatient Visit With a High Level of Medical Decision Making, If Using Time, 60 Minutes Or More99205 | 18 | $190 |
| New Patient Office Or Other Outpatient Visit With a High Level of Medical Decision Making, If Using Time, 60 Minutes Or More |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 26 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Hydrocodone/Acetaminophenbrand: Hydrocodone-Acetaminophen | 159 | 33 |
| Ondansetron Hcl | 87 | 59 |
| Prochlorperazine Maleate | 83 | 44 |
| Loperamide Hclbrand: Loperamide | 59 | 24 |
| Oxycodone Hcl | 48 | 13 |
| Alprazolam | 42 | — |
| Pantoprazole Sodium |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$70 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
Registry dates
- Enumerated
- 2006-03-25
- Last updated
- 2011-04-14
Frequently asked questions
- What is William Leslie's NPI number?
- William Leslie's National Provider Identifier (NPI) is 1538129275, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Leslie's specialty?
- William Leslie is listed in the NPPES registry with a primary specialty of Hematology & Oncology Physician (Allopathic & Osteopathic Physicians).
- Where is William Leslie located?
- William Leslie's practice location on file with NPPES is 1725 W Harrison St, Chicago, IL 60612-3841.
- What is William Leslie's phone number?
- The practice phone number listed in the NPPES registry for William Leslie is (312) 942-5904.
- Does William Leslie accept Medicare?
- William Leslie is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is William Leslie's NPI active?
- Yes — William Leslie's NPI (1538129275) is active in the NPPES registry as of the last update on 2011-04-14.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.