In 1977 Transitional Services of New York for Long Island, Inc. (TSLI), became the first community residence program serving psychiatrically disabled adults  on Long Island, when it began operation as a division of Transitional Services for New York, Inc. (TSI), based in Queens County, New York. 

TSI/Queens resulted from the efforts of a group of parents of mentally ill young adults who banded together in 1975 to seek alternatives to long-term hospitalization.  The program was based on a model already operational in Buffalo and Pittsburgh.  The positive results and cost effectiveness shown by these early programs established the trend followed by many residential programs.

TSLI became a separate not-for-profit corporation in 1981 and has grown from a twenty-four bed program into one of the largest community residence programs on Long Island. TSLI has 501 (c)(3) tax exempt  status.

TSLI operates several programs that serve psychiatrically disabled adults on Long Island, New York:

Pathways

Transitional housing and support services serving psychiatrically disabled adults

Summit 

Permanent housing with support services for mentally ill individuals and families who were formerly homeless

Maintenance Opportunity Program

Supported work opportunities for psychiatrically disabled adults