William Clark, MD
NPI 1891903696 · Hematology & Oncology Physician · Richmond, VA
Enrolled with Medicare as Practitioner - Hematology/Oncology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
William Clark, MD is a Hematology & Oncology Physician provider in Richmond, VA (NPI 1891903696).
Provider details
- NPI number
- 1891903696
- Entity type
- Individual
- Primary specialty
- Hematology & Oncology PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- 0116016320 (VA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Student, Health Care
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
622 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 50 Minutes99233 | 283 | $113 |
| Established Patient Office Or Other Outpatient Visit With High Level of Medical Decision Making, If Using Time, 40 Minutes Or More99215 | 111 | $136 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 85 | $92 |
| Hospital Discharge Day Management, More Than 30 Minutes99239 | 39 | $109 |
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 35 Minutes99232 | 37 | $75 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 7 distinct drugs on file.
| Drug | Part D claims (2024) |
|---|---|
| Atovaquone | 26 |
| Prednisone | 24 |
| Acyclovir | 19 |
| Lenalidomide | 19 |
| Montelukast Sodium | 18 |
| Ondansetron Hcl | 13 |
| Pen Needle, Diabeticbrand: Droplet Pen Needle | 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.
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$179 across 2 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
- 2007-05-18
- Last updated
- 2013-02-08
Frequently asked questions
- What is William Clark's NPI number?
- William Clark's National Provider Identifier (NPI) is 1891903696, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Clark's specialty?
- William Clark is listed in the NPPES registry with a primary specialty of Hematology & Oncology Physician (Allopathic & Osteopathic Physicians).
- Where is William Clark located?
- William Clark's practice location on file with NPPES is 1300 E Marshall St, Richmond, VA 23298-5054.
- What is William Clark's phone number?
- The practice phone number listed in the NPPES registry for William Clark is (804) 628-5054.
- Does William Clark accept Medicare?
- William Clark is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is William Clark's NPI active?
- Yes — William Clark's NPI (1891903696) is active in the NPPES registry as of the last update on 2013-02-08.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.