Quick answers
- Which hospitals does John M. Costable Jr. work at?
- Medicare's official clinician data lists John M. Costable Jr. at 1 hospital: Mount Sinai South Nassau. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does John M. Costable Jr. see patients?
- Medicare's clinician data lists 2 practice locations, including Manhasset, NY and Hewlett, NY. Call before your visit to confirm the address.
- What is John M. Costable Jr.'s specialty?
- Medicare lists Gastroenterology as the primary specialty, and also Internal Medicine.
- Does John M. Costable Jr. accept Medicare assignment?
- Yes. Medicare's clinician data says John M. Costable Jr. accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of 2026-10-02. Ask the office to confirm before your visit.
- What is the phone number for John M. Costable Jr.?
- (516) 390-2850, as listed in official Medicare / NPI Registry data.
- What is John M. Costable Jr.'s NPI number?
- 1043251184. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where John M. Costable Jr. works
Medicare's Facility Affiliation Data lists John M. Costable Jr. at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Mount Sinai South NassauOceanside, NY · Acute Care Hospital · CCN 330198
Practice locations
Addresses where John M. Costable Jr. is enrolled with Medicare (CMS data updated 2026-10-02).
- 1155 Northern BlvdManhasset, NY 11030 (516) 390‑2850
- 1436 BroadwayHewlett, NY 11557 (929) 210‑6570
Group practices
Medicare enrollment lists John M. Costable Jr. as a member of this group (CMS data updated 2026-10-02).
- North Shore Medical Group of the Mount Sinai School of Medicine331 clinicians in the group
Specialties
- Gastroenterologyprimary
- Internal Medicinealso
Other gastroenterologists in Manhasset
Clinicians with the same Medicare primary specialty in Manhasset, NY — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | State University Of New York At Stony Brook, School Of Medicine |
| Graduation year | 1992 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1043251184 |
| Corrections | Report an error or suggest an update → |
Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.
Sources
- Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated 2026-10-02, retrieved 2026-10-29
- National Downloadable File (Doctors and Clinicians) — CMS, data updated 2026-10-02, retrieved 2026-10-29
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians