John Oppenheimer, M.D.
NPI 1659364214 · Internal Medicine Physician · Sag Harbor, NY
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
John Oppenheimer, M.D. is a Internal Medicine Physician provider in Sag Harbor, NY (NPI 1659364214).
Provider details
- NPI number
- 1659364214
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- Yes
- License
- 150853 (NY)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
20 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
623 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) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 311 | $76 |
| Established Patient Office Or Other Outpatient Visit With High Level of Medical Decision Making, If Using Time, 40 Minutes Or More99215 | 141 | $159 |
| Administration of Influenza Virus VaccineG0008 | 82 | $24 |
| Administration of Pneumococcal VaccineG0009 | 47 | $24 |
| Established Patient Office Or Other Outpatient Visit With Straightforward Medical Decision Making, If Using Time, 10 Minutes Or More99212 | 23 | $49 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 92 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Atorvastatin Calcium | 243 | 67 |
| Levothyroxine Sodium | 136 | 32 |
| Amlodipine Besylate | 124 | 36 |
| Losartan Potassium | 119 | 35 |
| Escitalopram Oxalate | 111 | 27 |
| Montelukast Sodium | 107 | 25 |
| Rosuvastatin Calcium |
Practice location
Mailing address
Registry dates
- Enumerated
- 2005-08-29
- Last updated
- 2009-08-21
Frequently asked questions
- What is John Oppenheimer's NPI number?
- John Oppenheimer's National Provider Identifier (NPI) is 1659364214, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is John Oppenheimer's specialty?
- John Oppenheimer is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is John Oppenheimer located?
- John Oppenheimer's practice location on file with NPPES is 60 Bay St, Sag Harbor, NY 11963-3106.
- What is John Oppenheimer's phone number?
- The practice phone number listed in the NPPES registry for John Oppenheimer is (631) 725-4600.
- Does John Oppenheimer accept Medicare?
- John Oppenheimer is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is John Oppenheimer's NPI active?
- Yes — John Oppenheimer's NPI (1659364214) is active in the NPPES registry as of the last update on 2009-08-21.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.