Gregg G. Marella, MD

Medicare activity in 2024

Official CMS public-use data for Gregg G. Marella, data year 2024 (released May 21, 2026). It covers Original Medicare (fee-for-service) patients only, not Medicare Advantage or other insurance. It shows volume, not quality or outcomes. CMS hides any count of 10 or fewer patients.

Most frequent services

1. Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)538 services
2. Visit complexity inherent to evaluation and management associated with medical care services that serve as the continuing focal point for all needed health care services and/or with medical care services that are part of ongoing care related to a patient's (G2211)336 services
3. Insertion of needle into vein for collection of blood sample (36415)303 services
4. Residence visit for established patient with moderate level of medical decision making, per day, if using time, at least 40 minutes (99349)123 services
5. Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)95 services

Chronic conditions among these patients

Share of this clinician’s Original Medicare patients with each condition, as published by CMS (it describes the patients, not the care given).

• High blood pressure75%
• High cholesterol75%
• Arthritis40%
• Diabetes24%
• Ischemic heart disease19%
• Anxiety16%

Hospitals where Gregg G. Marella works

Medicare's Facility Affiliation Data lists Gregg G. Marella at these hospitals (updated October 2, 2026). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians. Star rating and emergency services: Hospital General Information (CMS), data updated October 26, 2026.

• Morristown Medical CenterMorristown, NJ · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 310015

Practice locations

Addresses where Gregg G. Marella is enrolled with Medicare (CMS data updated October 2, 2026).

• 19 E Main St, Suite 1Mendham, NJ 07945 (973) 543‑6505

Specialties

• Internal Medicineprimary

Find other Internal Medicine doctors in New Jersey →

Other internal medicine doctors in New Jersey

Clinicians with the same Medicare primary specialty in New Jersey — not a recommendation.

• Christie J. Prestifilippo, MD
• Allison C. Connolly, MD
• Ghalia Hanif, MD
• Maria Khan, MD
• Lisa F. Brodkin, MD
• Jay Naik, MD
• Palakkumar Patel, MD
• Gilda E. Ganzon-Zampino, MD

All internal medicine doctors in New Jersey →

Clinician information

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

1. Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated October 2, 2026, retrieved October 29, 2026
2. Hospital General Information — CMS, data updated October 26, 2026, retrieved November 13, 2026
3. National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
4. Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
5. NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
6. Medicare Care Compare — official Medicare tool to look up clinicians