The Department of Developmental Services (DDS) has a long history in the State of Connecticut.  As early as 1917, services for individuals with mental retardation (now known as intellectual disability) were largely provided at the Mansfield Training School until 1940 when the Southbury Training School was opened.  Eventually, these facilities, along with “Regional Centers” established in the 1960s, were overseen by the Office of Mental Retardation, a division of the State Department of Health. 
In 1975 the Connecticut General Assembly established an independent Department of Mental Retardation (P.A. No. 75-638), in the executive branch, headed by a Commissioner appointed by the Governor.  Although DDS continues to directly operate both congregate and community-based services and supports, the department's focus has largely become community-based relying upon a network of DDS qualified private providers. 
The result is a statewide system which provides support and services to persons with intellectual disability who reside in family homes, independently, in state-operated residential facilities, in licensed "community companion homes" and in more than 850 licensed or certified "community living arrangements." Since 1987, most services and supports provided by DDS have been subject to federal reimbursement under Medicaid Home and Community Based Services Waivers, which are approved by the Centers for Medicaid and Medicare Services (CMS).
In 2007, persons who advocated for the elimination of the “R” word saw the department change its name from the Department of Mental Retardation to the Department of Developmental Services.  In 2011, the “R” word was removed from most state statutes and the term “intellectual disability” was substituted.  In 2015, the definition of “mental retardation” in section 1-1g of the general statutes was changed to “intellectual disability” to align the definition with the APA’s Diagnostics and Statistics Manual (DSM-5) These changes reflect the mission and commitment of the department to serve individuals with the utmost respect and dignity.

More recently, DDS has promoted more independent models of service provision for individuals in the community including self-directed services, in-home supports, and the use of assistive technology. Competitive employment as an option for all individuals has become a goal of the department as part of the integration of individuals with intellectual disability into communities of their choice.