The Trust board chairwoman Keryn Brass said it was not a decision made lightly.
"We are confident that this decision is in the best interests of the Southern Tararua community."
The Trust, which was once known as Pahiatua Community Services Trust, began as a small counselling service and evolved to a one-stop shop for all the community's needs.
Brass said the founders had established the organisation with a vision of being able to provide the community with social services and ensure they were available to all.
"This vision has become a reality and over time the organisation has evolved into something far greater and more meaningful to our community that we could have hoped for."
She said it hadn't been easy navigating a small non-government organisation through hoops and keeping it financially afloat.
"We are grateful for the support we have received from funders and community donations over the years."
Anglican Care Waiapu (ACW) was the social services arm of the Anglican Diocese of Waiapu with programmes including early childhood centres, older people's programmes such as the Elske Centre in Dannevirke, family services and Growing Through Grief.
ACW chief executive officer Lucy Laitinen said joining the two services to become Tararua Community Services would allow the much needed services provided by The Trust to continue within the wider whanau support system of ACW.
"I want to acknowledge the efforts of current and former The Trust trustees who have given so much of their time, energy, and talents to the community over the years."
The Trust manager Kelly Wylie has moved into the role of manager of Tararua Community Services.
Laitinen said staff from The Trust had spent part of the first week attending training on new ACW systems and processes but otherwise had got on with work as usual.
She said there would be no changes in service provision.
"We just now have a wider footprint and over time will be able to strengthen our current offerings by having a larger presence."
The newly established service would continue to provide a wide range of services across the Tararua district including social work, counselling, parenting support, pregnancy testing and access to midwives, support for the elderly, family and youth programmes.