William Whittier, MD
NPI 1609981471 · Nephrology Physician · Chicago, IL
Enrolled with Medicare as Practitioner - Nephrology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
William Whittier, MD is a Nephrology Physician provider in Chicago, IL (NPI 1609981471).
Provider details
- NPI number
- 1609981471
- Entity type
- Individual
- Primary specialty
- Nephrology PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- 036104632 (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
19 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
1,441 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) |
|---|---|---|
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 35 Minutes99232 | 337 | $80 |
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 50 Minutes99233 | 306 | $120 |
| Hemodialysis Procedure With Physician Evaluation90935 | 214 | $71 |
| Initial Hospital Care With Moderate Level of Medical Decision Making, If Using Time, at Least 75 Minutes99223 | 164 | $175 |
| Dialysis Services, 4 Or More Physician Visits Per Month (20 Years Or Older)90960 | 161 | $354 |
| Established Patient Office Or Other Outpatient Visit With High Level of Medical Decision Making, If Using Time, 40 Minutes Or More99215 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 19 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Valsartan | 65 | 16 |
| Carvedilol | 58 | 16 |
| Potassium Citratebrand: Potassium Citrate Er | 56 | 21 |
| Amlodipine Besylate | 53 | 13 |
| Furosemide | 50 | 16 |
| Spironolactone | 42 | 13 |
| Chlorthalidone | 35 | — |
| Sevelamer Carbonate |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$412 across 6 records (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
- 2006-08-20
- Last updated
- 2025-04-29
- Certified
- 2025-04-29
Frequently asked questions
- What is William Whittier's NPI number?
- William Whittier's National Provider Identifier (NPI) is 1609981471, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Whittier's specialty?
- William Whittier is listed in the NPPES registry with a primary specialty of Nephrology Physician (Allopathic & Osteopathic Physicians).
- Where is William Whittier located?
- William Whittier's practice location on file with NPPES is 104 S Ashland Ave, Chicago, IL 60607-2402.
- What is William Whittier's phone number?
- The practice phone number listed in the NPPES registry for William Whittier is (312) 850-8434.
- Does William Whittier accept Medicare?
- William Whittier is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is William Whittier's NPI active?
- Yes — William Whittier's NPI (1609981471) is active in the NPPES registry as of the last update on 2025-04-29.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.