Quick answers
- Which hospitals does Leon Mullen work at?
- Medicare's official clinician data lists Leon Mullen at 5 hospitals: Long Island Jewish Medical Center, Mercy Medical Center, Mount Sinai South Nassau, NYU Langone Hospitals and St Francis Hospital - The Heart Center. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Leon Mullen see patients?
- Medicare's clinician data lists 2 practice locations, including Rockville Center, NY and East Meadow, NY. Call before your visit to confirm the address.
- What is Leon Mullen's specialty?
- Medicare lists Cardiovascular Disease (Cardiology) as the primary specialty.
- Does Leon Mullen accept Medicare assignment?
- Yes. Medicare's clinician data says Leon Mullen 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 Leon Mullen?
- (516) 705-1353, as listed in official Medicare / NPI Registry data.
- What is Leon Mullen's NPI number?
- 1497831986. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Leon Mullen works
Medicare's Facility Affiliation Data lists Leon Mullen at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Long Island Jewish Medical CenterNew Hyde Park, NY · Acute Care Hospital · CCN 330195
- Mercy Medical CenterRockville Centre, NY · Acute Care Hospital · CCN 330259
- Mount Sinai South NassauOceanside, NY · Acute Care Hospital · CCN 330198
- NYU Langone HospitalsNew York, NY · Acute Care Hospital · CCN 330214
- St Francis Hospital - The Heart CenterRoslyn, NY · Acute Care Hospital · CCN 330182
Practice locations
Addresses where Leon Mullen is enrolled with Medicare (CMS data updated 2026-10-02).
- 1000 N Village AveRockville Center, NY 11570 (516) 705‑1353
- 30 Merrick Ave, Suite 105East Meadow, NY 11554 (516) 542‑0255
Group practices
Medicare enrollment lists Leon Mullen as a member of this group (CMS data updated 2026-10-02).
- Mercy Internal Medicine PC10 clinicians in the group
Specialties
Find other Cardiovascular Disease (Cardiology) doctors in New York →
Other cardiologists in Rockville Center
Clinicians with the same Medicare primary specialty in Rockville Center, NY — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 1976 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1497831986 |
| 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