William Ewen, M.D.
NPI 1538355490 · Emergency Medicine Physician · Round Rock, TX
Enrolled with Medicare as Practitioner - Emergency Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
William Ewen, M.D. is a Emergency Medicine Physician provider in Round Rock, TX (NPI 1538355490).
Provider details
- NPI number
- 1538355490
- Entity type
- Individual
- Primary specialty
- Emergency Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- N6286 (TX)
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 tenure28% of score
18 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
2 documented practice locations
- Medicare service volume (vs. specialty peers)28% of score
501 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) |
|---|---|---|
| Emergency Department Visit With High Level of Medical Decision Making99285 | 260 | $178 |
| Emergency Department Visit With Moderate Level of Medical Decision Making99284 | 156 | $124 |
| Critical Care, First 30-74 Minutes99291 | 58 | $214 |
| Emergency Department Visit With Low Level of Medical Decision Making99283 | 27 | $73 |
Typical Medicare-allowed amounts for these services range $73–$214 (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 · 8 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Cephalexin | 31 | 31 |
| Tramadol Hcl | 24 | 24 |
| Ondansetronbrand: Ondansetron Odt | 19 | 19 |
| Methylprednisolone | 18 | 18 |
| Acetaminophen With Codeinebrand: Acetaminophen-Codeine | 15 | 13 |
| Naproxen Sodium | 14 | 14 |
| Ciprofloxacin Hcl | 12 | 12 |
Practice location
Mailing address
Additional practice locations (1)
- 5323 Harry Hines Blvd.Mc 8579Dallas, TX 75390-8579Phone: (214) 648-3916Fax: (214) 648-8423
Registry dates
- Enumerated
- 2007-09-24
- Last updated
- 2026-01-21
- Certified
- 2026-01-21
Frequently asked questions
- What is William Ewen's NPI number?
- William Ewen's National Provider Identifier (NPI) is 1538355490, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Ewen's specialty?
- William Ewen is listed in the NPPES registry with a primary specialty of Emergency Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is William Ewen located?
- William Ewen's practice location on file with NPPES is 300 University Blvd, Round Rock, TX 78665-1032.
- What is William Ewen's phone number?
- The practice phone number listed in the NPPES registry for William Ewen is (512) 509-0100.
- Does William Ewen accept Medicare?
- William Ewen is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is William Ewen's NPI active?
- Yes — William Ewen's NPI (1538355490) is active in the NPPES registry as of the last update on 2026-01-21.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.