Fred Williams, MD
NPI 1386644326 · Gastroenterology Physician · Chesterfield, MO
Enrolled with Medicare as Practitioner - Gastroenterology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Fred Williams, MD is a Gastroenterology Physician provider in Chesterfield, MO (NPI 1386644326).
Provider details
- NPI number
- 1386644326
- Entity type
- Individual
- Primary specialty
- Gastroenterology PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- 118411 (MO)
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
20 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
127 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) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 41 | $124 |
| Pathology Examination of Tissue Using a Microscope, Intermediate Complexity88305 | 30 | $34 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 21 | $87 |
| New Patient Office Or Other Outpatient Visit With Moderate Level of Medical Decision Making, If Using Time, 45 Minutes Or More99204 | 19 | $156 |
| New Patient Office Or Other Outpatient Visit With Low Level of Medical Decision Making, If Using Time, 30 Minutes Or More99203 | 16 | $108 |
Typical Medicare-allowed amounts for these services range $34–$156 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, 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 · 10 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Pantoprazole Sodium | 115 | 36 |
| Famotidine | 57 | 19 |
| Sodium, Potassium,mag Sulfatesbrand: Sod Sulf-Potass Sulf-Mag Sulf | 36 | 36 |
| Mesalamine | 35 | 13 |
| Omeprazole | 30 | 12 |
| Colestipol Hcl | 28 | 17 |
| Budesonidebrand: Budesonide Dr | 20 | — |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$140 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
- 2005-07-29
- Last updated
- 2017-04-12
Frequently asked questions
- What is Fred Williams's NPI number?
- Fred Williams's National Provider Identifier (NPI) is 1386644326, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Fred Williams's specialty?
- Fred Williams is listed in the NPPES registry with a primary specialty of Gastroenterology Physician (Allopathic & Osteopathic Physicians).
- Where is Fred Williams located?
- Fred Williams's practice location on file with NPPES is 121 Saint Lukes Center Dr, Chesterfield, MO 63017-3509.
- What is Fred Williams's phone number?
- The practice phone number listed in the NPPES registry for Fred Williams is (314) 432-5900.
- Does Fred Williams accept Medicare?
- Fred Williams is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Fred Williams's NPI active?
- Yes — Fred Williams's NPI (1386644326) is active in the NPPES registry as of the last update on 2017-04-12.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.