John Joseph Gregory, M.D.
Pediatric Hematology & Oncology Physician · Morristown, NJ
John Joseph Gregory, M.D. is a pediatric hematology & oncology physician with a practice address in Morristown, New Jersey, and NPI 1457307340, issued on May 25, 2006. Check the license (New Jersey 25MA06944600, as entered in NPPES) on the New Jersey State Board of Medical Examiners; the federal record below is the public data PlainDoctor holds for this provider.
- Name
- John Joseph Gregory
- Credential
- M.D.
- Primary taxonomy
- Pediatric Hematology & Oncology Physician 2080P0207X
- License number
- 25MA06944600 NJ
Self-reported in NPPES; status is on the state search - Practice location
- 100 Madison Ave, Morristown, NJ 07960
- Phone
- (973) 971-6720
- Enumerated
- May 25, 2006
- Record last updated
- Mar 25, 2008 (not updated in 18 years: call before relying on the address or phone)
- Fax
- (973) 401-2410
- Medicaid ID
- 02257165 NY
- Entity
- Type 1 · individual
8 nearest pediatric hematology & oncology physician records → All 71 in New Jersey → Look up another NPI →
Also registered at 100 Madison Ave
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- Arkadiy Abkin, MDAnesthesiology Physician1316928666
Verify John Joseph Gregory in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersNew Jersey State Board of Medical Examiners
Search for license 25MA06944600Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
John Joseph Gregory among 71 pediatric hematology & oncology physician records in New Jersey
John Joseph Gregory, M.D. is one of 71 pediatric hematology & oncology physician records with a practice address in New Jersey. 44% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does not. Its NPI, issued in 2006, is newer than 1% of them.
- NPI issued2006 · 1% of these records are older, 56% newer
- In a Medicare fileNo · 44% of these records are
- In the CMS Doctors and Clinicians fileNo · 15% of these records are
- Record last updated2008 · 56% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 2080P0207X and a New Jersey practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Pediatric Hematology & Oncology Physician providers in New Jersey
There are 71 pediatric hematology & oncology physician records in New Jersey. No Medicare prescribing, quality score, industry payment or hospital affiliation is published for this NPI.
All 71 in New Jersey → Every provider in Morristown → Pediatric Hematology & Oncology Physician nationwide →
The 8 pediatric hematology & oncology physician records with the nearest ZIP codes
- Melinda Fritz, MDMorristown, NJ 079601922184688
- Tamara Hagoel, D.O.Morristown, NJ 079601508285123
- Steven Halpern, MDMorristown, NJ 079601396791117
- Stacey Kalambakas, MDMorristown, NJ 079601285606335
- Kathryn Laurie, M.D.Morristown, NJ 079601245673912
- Hazen Mahmoud, MDMorristown, NJ 079601134192495
- Michelle Miller, MDMorristown, NJ 079601699748699
- Fadi Nossair, MDCMMorristown, NJ 079601316100407
Common questions
What is John Joseph Gregory, M.D.'s NPI number?
John Joseph Gregory, M.D.'s National Provider Identifier (NPI) is 1457307340, issued on May 25, 2006. An NPI identifies a provider in billing; it is not a license.
Where is John Joseph Gregory, M.D. located?
The NPPES record lists a practice address at 100 Madison Ave, Morristown, NJ, 07960. Phone: (973) 971-6720. Providers update this record themselves, so call before visiting.
How can I verify John Joseph Gregory, M.D.'s license?
NPPES lists New Jersey license number 25MA06944600, as entered by the provider. Search the New Jersey State Board of Medical Examiners at https://newjersey.mylicense.com/verification/. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. 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.