QOPS Exterior

Quannacut Outpatient Services addresses patients’ immediate and long-term substance use issues, as well as the impact on their support system, family members, and significant others. Centrally located in Riverhead, the facility provides highly individualized programs for patients with diverse needs across a wide variety of treatment disciplines so that patients can receive all outpatient care in one location.  Treatment is provided by a multidisciplinary treatment team of physicians, psychiatrists, social workers and peers.

Stony Brook Medicine Quannacut Outpatient Services
905 East Main Street, Riverhead, NY 11901
(631) 369-8966
Please note: Using GPS for directions to the Quannacut office may lead to the residential home. We suggest using Google Maps for best driving directions to the office.


  • Telehealth services
  • Co-occurring services
  • Medical psycho-therapeutic approach
  • Completely individualized treatment
  • Individual, family, spousal, and group psychotherapy
  • Specialty Groups including Young Adults, Women, Co-occurring Disorders, and Advanced Recovery
  • Medication for Opioid Use Disorder Treatment (MOUD)
  • Medication for Alcohol UseDisorder Treatment (MAUD)
  • Psychiatric evaluations and medication management services
  • Primary care medical services
  • NYS Department of Motor Vehicle Treatment site 
  • Two recovery homes
  • Off-site services at SBELIH and Stony Brook Southampton Hospital
  • Adolescents ages 14-17


    Monday: 9 am - 8 pm
    Tuesday: 9 am - 5 pm
    Wednesday: 9 am - 8 pm
    Thursday: 9 am - 8 pm
    Friday: 9 am - 2 pm
    Saturday: 8:30 am -12:30 pm

    Offsite Locations:

    291 Hampton Road, Southampton, NY 11968
    Monday, Tuesday, and Thursday

    201 Manor Place, Greenport, NY 11944
    Tuesday and Thursday


    • Intake assessments by appointment: Monday-Saturday
    • Walk-in intake assessments: Mondays and Fridays from 9 am - 12 pm

    Jarid Pachter, DO 
    SBUH Medical Board
    Medical Director of Quannacut Outpatient Services
    Diplomate, American Osteopathic Association, Family Medicine
    Diplomate, American Society of Addiction Medicine

    Riverhead: (631) 369-8966 / Southold: (631) 734-8742

    Elizabeth Day, LCSW, CAMS-II 
    Director, Outpatient Addiction Services, Quannacut Outpatient Services
    Riverhead: (631) 369-8966

    Douglas K. Hoverkamp, MD
    Psychiatric Director, Quannacut Outpatient Services
    Director, Department of Psychiatry, SBELIH
    Diplomate, American Board of Psychiatry
    Riverhead: (631) 369-8966 / Greenport: (631) 477-6890