William Farmer, D.O.
NPI 1558374850 · Gastroenterology Physician · Hattiesburg, MS
Enrolled with Medicare as Practitioner - Emergency Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
William Farmer, D.O. is a Gastroenterology Physician provider in Hattiesburg, MS (NPI 1558374850).
Provider details
- NPI number
- 1558374850
- Entity type
- Individual
- Primary specialty
- Gastroenterology PhysicianAllopathic & Osteopathic Physicians
- Credential
- D.O.
- Sex
- Male
- Sole proprietor
- No
- License
- 18326 (MS)
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
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
1,784 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 Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 319 | $82 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 209 | $116 |
| Biopsy of Esophagus, Stomach, And/Or Upper Small Bowel Using a Flexible Endoscope43239 | 149 | $77 |
| Removal of Polyps Or Growths of Large Bowel Using an Endoscope With Mechanical Snare45385 | 147 | $229 |
| Biopsy of Large Bowel Using a Flexible Endoscope45380 | 132 | $92 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 19 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Pantoprazole Sodium | 194 | 80 |
| Sod Picosulf/Mag Ox/Citric Acbrand: Clenpiq | 103 | 101 |
| Sodium Chloride/Nahco3/Kcl/Pegbrand: Peg 3350-Electrolyte | 103 | 101 |
| Omeprazole | 66 | 25 |
| Famotidine | 58 | 18 |
| Linaclotidebrand: Linzess | 46 | 16 |
| Dicyclomine Hcl | 45 |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$2,063 across 113 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
- 2006-08-15
- Last updated
- 2016-09-14
Frequently asked questions
- What is William Farmer's NPI number?
- William Farmer's National Provider Identifier (NPI) is 1558374850, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Farmer's specialty?
- William Farmer is listed in the NPPES registry with a primary specialty of Gastroenterology Physician (Allopathic & Osteopathic Physicians).
- Where is William Farmer located?
- William Farmer's practice location on file with NPPES is 100 Methodist Blvd, Hattiesburg, MS 39402-1295.
- What is William Farmer's phone number?
- The practice phone number listed in the NPPES registry for William Farmer is (601) 268-5185.
- Does William Farmer accept Medicare?
- William Farmer is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is William Farmer's NPI active?
- Yes — William Farmer's NPI (1558374850) is active in the NPPES registry as of the last update on 2016-09-14.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.