Warren Fields, M.D.
NPI 1821083999 · Internal Medicine Physician · Mystic, CT
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Warren Fields, M.D. is a Internal Medicine Physician provider in Mystic, CT (NPI 1821083999).
Provider details
- NPI number
- 1821083999
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- 035098 (CT)
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
1,874 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) |
|---|---|---|
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 35 Minutes99232 | 688 | $80 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 386 | $138 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 203 | $99 |
| Annual Wellness Visit, Includes a Personalized Prevention Plan of Service (pps), Subsequent VisitG0439 | 133 | $141 |
| Hemoglobin A1c Level83036 | 89 | $10 |
| Hospital Discharge Day Management, More Than 30 Minutes99239 | 84 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 147 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Atorvastatin Calcium | 434 | 126 |
| Losartan Potassium | 315 | 94 |
| Alprazolam | 306 | 60 |
| Pantoprazole Sodium | 275 | 94 |
| Amlodipine Besylate | 227 | 71 |
| Levothyroxine Sodium | 225 | 55 |
| Lisinopril |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$137 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
- 2005-09-15
- Last updated
- 2009-12-22
Frequently asked questions
- What is Warren Fields's NPI number?
- Warren Fields's National Provider Identifier (NPI) is 1821083999, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Warren Fields's specialty?
- Warren Fields is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Warren Fields located?
- Warren Fields's practice location on file with NPPES is 200 Sandy Hollow Rd, Mystic, CT 06355-1720.
- What is Warren Fields's phone number?
- The practice phone number listed in the NPPES registry for Warren Fields is (860) 572-8911.
- Does Warren Fields accept Medicare?
- Warren Fields is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Warren Fields's NPI active?
- Yes — Warren Fields's NPI (1821083999) is active in the NPPES registry as of the last update on 2009-12-22.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.