John Williamson, M.D.
NPI 1043308661 · Family Medicine Physician · Charleston, SC
Enrolled with Medicare as Practitioner - Family Practice · source: CMS PECOS Public Provider Enrollment (2026.04.01)
John Williamson, M.D. is a Family Medicine Physician provider in Charleston, SC (NPI 1043308661).
Provider details
- NPI number
- 1043308661
- Entity type
- Individual
- Primary specialty
- Family Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- 44600 (TN)
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
19 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
784 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 35 Minutes99232 | 443 | $73 |
| Hospital Discharge Day Management, More Than 30 Minutes99239 | 184 | $106 |
| Initial Hospital Care With Moderate Level of Medical Decision Making, If Using Time, at Least 75 Minutes99223 | 101 | $161 |
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 50 Minutes99233 | 56 | $111 |
Typical Medicare-allowed amounts for these services range $73–$161 (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 · 6 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Atorvastatin Calcium | 25 | 13 |
| Prednisone | 24 | 23 |
| Amoxicillin/Potassium Clavbrand: Amoxicillin-Clavulanate Potass | 24 | 23 |
| Amlodipine Besylate | 17 | — |
| Cefdinir | 12 | 12 |
| Furosemide | 12 | — |
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 , 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.
Practice location
Mailing address
Additional practice locations (1)
- 4095 American Way 1Suite 1Memphis, TN 38118-8339Phone: (901) 271-9500Fax: (901) 271-9501
Registry dates
- Enumerated
- 2006-10-10
- Last updated
- 2022-07-09
- Certified
- 2022-07-09
Frequently asked questions
- What is John Williamson's NPI number?
- John Williamson's National Provider Identifier (NPI) is 1043308661, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is John Williamson's specialty?
- John Williamson is listed in the NPPES registry with a primary specialty of Family Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is John Williamson located?
- John Williamson's practice location on file with NPPES is 316 Calhoun St, Charleston, SC 29401-1113.
- What is John Williamson's phone number?
- The practice phone number listed in the NPPES registry for John Williamson is (843) 402-1000.
- Does John Williamson accept Medicare?
- John Williamson is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is John Williamson's NPI active?
- Yes — John Williamson's NPI (1043308661) is active in the NPPES registry as of the last update on 2022-07-09.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.