John K. Oppenheimer, M.D.
Internal Medicine Physician · Sag Harbor, NY
John K. Oppenheimer, M.D. is an internal medicine physician with a practice address in Sag Harbor, New York, and NPI 1659364214, issued on Aug 29, 2005. Check the license (New York 150853, as entered in NPPES) on the NYS Education Department, Office of the Professions; the Medicare figures below come from public CMS files.
- Name
- John K. Oppenheimer
- Credential
- M.D.
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- 150853 NY
Self-reported in NPPES; status is on the state search - Practice location
- 60 Bay St, Sag Harbor, NY 11963
- Phone
- (631) 725-4600
- Enumerated
- Aug 29, 2005
- Record last updated
- Aug 21, 2009 (not updated in 17 years: call before relying on the address or phone)
- Fax
- (631) 725-6073
- Medicare enrollment
- Enrolled (PECOS I20100303000200); accepts Medicare assignment
- Medical or professional school
- Tulane University School Of Medicine, 1981
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 12,067 in New York → Look up another NPI →
Verify John K. Oppenheimer in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersNYS Education Department, Office of the Professions
Search for license 150853Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
25% more Medicare Part D claims than the average internal medicine physician in 2024
3,958 Medicare Part D claims for 216 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 15% of claims. 74 claims were for opioids.
Most prescribed
- Atorvastatin Calcium243 claims
- Levothyroxine Sodium136 claims
- Amlodipine Besylate124 claims
- Losartan Potassium119 claims
- Escitalopram Oxalate111 claims
- Montelukast Sodium107 claims
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
John K. Oppenheimer among 12,067 internal medicine physician records in New York
John K. Oppenheimer, M.D. is one of 12,067 internal medicine physician records with a practice address in New York. 79% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2005, is newer than 0% of them.
- NPI issued2005 · 0% of these records are older, 92% newer
- In a Medicare fileYes · 79% of these records are
- In the CMS Doctors and Clinicians fileYes · 60% of these records are
- Graduated1981 · median 2002 among the 7,221 with a school on file
- Record last updated2009 · 61% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207R00000X and a New York practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
2 internal medicine physician records list a practice address in Sag Harbor
They are 2 of the 83 NPPES records with a practice address in Sag Harbor, and 12,067 internal medicine physician records in New York.
All 12,067 in New York → Every provider in Sag Harbor → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Victoria Sharp, M.D.Sag Harbor, NY 119631942425798
- Karina Appel, MDShirley, NY 119671184250151
- Shu Wang, MDShirley, NY 119671639188857
- Charles Arcoleo, MDSouthampton, NY 119681770659054
- Carmen Chinea, M.D.Southampton, NY 119681619995941
- Candace Cummings, M.D.Southampton, NY 119681336252782
- Charles Guida, MDSouthampton, NY 119681144288143
- Thomas Mathew, M.D.Southampton, NY 119681336363373
Common questions
What is John K. Oppenheimer, M.D.'s NPI number?
John K. Oppenheimer, M.D.'s National Provider Identifier (NPI) is 1659364214, issued on Aug 29, 2005. An NPI identifies a provider in billing; it is not a license.
Where is John K. Oppenheimer, M.D. located?
The NPPES record lists a practice address at 60 Bay St, Sag Harbor, NY, 11963. Phone: (631) 725-4600. Providers update this record themselves, so call before visiting.
How can I verify John K. Oppenheimer, M.D.'s license?
NPPES lists New York license number 150853, as entered by the provider. Search the NYS Education Department, Office of the Professions at https://www.op.nysed.gov/services/verifications/online-verification-searches. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does John K. Oppenheimer, M.D. prescribe under Medicare Part D?
In 2024, John K. Oppenheimer, M.D. had 3,958 Medicare Part D claims for 216 beneficiaries; the average among internal medicine physician prescribers was 3,176. Part D covers Medicare prescriptions only.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.