Calvin Williams, M.D. / PH.D
NPI 1023308640 · Infectious Disease Physician · Baltimore, MD
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Calvin Williams, M.D. / PH.D is a Infectious Disease Physician provider in Baltimore, MD (NPI 1023308640).
Provider details
- NPI number
- 1023308640
- Entity type
- Individual
- Primary specialty
- Infectious Disease PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D. / PH.D
- Sex
- Male
- Sole proprietor
- No
- License
- D0081038 (MD)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Student, Health Care
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
15 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
892 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) |
|---|---|---|
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 50 Minutes99233 | 457 | $120 |
| Initial Hospital Care With Moderate Level of Medical Decision Making, If Using Time, at Least 75 Minutes99223 | 353 | $174 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 82 | $95 |
Typical Medicare-allowed amounts for these services range $95–$174 (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 · 17 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Bictegrav/Emtricit/Tenofov Alabrand: Biktarvy | 188 | 23 |
| Elviteg/Cob/Emtri/Tenof Alafenbrand: Genvoya | 96 | 12 |
| Emtricitab/Rilpiviri/Tenof Alabrand: Odefsey | 57 | — |
| Abacavir/Dolutegravir/Lamivudibrand: Triumeq | 51 | — |
| Dolutegravir Sodiumbrand: Tivicay | 27 | — |
| Cephalexin | 21 | — |
| Emtricitabine/Tenofov Alafenam |
Practice location
Mailing address
Registry dates
- Enumerated
- 2011-04-15
- Last updated
- 2018-04-24
Frequently asked questions
- What is Calvin Williams's NPI number?
- Calvin Williams's National Provider Identifier (NPI) is 1023308640, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Calvin Williams's specialty?
- Calvin Williams is listed in the NPPES registry with a primary specialty of Infectious Disease Physician (Allopathic & Osteopathic Physicians).
- Where is Calvin Williams located?
- Calvin Williams's practice location on file with NPPES is 201 E University Pkwy, Baltimore, MD 21218-2829.
- What is Calvin Williams's phone number?
- The practice phone number listed in the NPPES registry for Calvin Williams is (443) 474-9911.
- Does Calvin Williams accept Medicare?
- Calvin Williams is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Calvin Williams's NPI active?
- Yes — Calvin Williams's NPI (1023308640) is active in the NPPES registry as of the last update on 2018-04-24.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.