Port Jefferson, N.Y.-based John T. Mather Memorial Hospital's board of directors signed a letter of intent to join New Hyde Park, N.Y.-based Northwell Health July 28.
The health systems will work together during the next few months to finalize an agreement, which will require approval from the boards of both hospitals and regulatory agencies. Officials expect to receive approval by the end of 2017.
The 248-bed Mather Memorial began affiliation discussions with several health systems in early 2016, eventually deciding on Northwell Health.
"Mather Hospital is known for patient-centric care both in the community and throughout the industry," said Michael J. Dowling, president and CEO of Northwell Health. "That deeply embedded sense of purpose is the type of quality we want to represent Northwell Health, along with an excellent staff of medical professionals and physicians. Together, Mather and Northwell will play a crucial partnership role expanding world class care and innovative patient services to Suffolk County residents."