Wales's qualifications, curriculum and assessment agency is to be taken over by the Assembly government, as part of first minister Rhodri Morgan's "bonfire of the quangos".
ACCAC's council had opposed the move, saying its work on regulating exams and the curriculum should be kept at arm's length from ministers. But the merger has been generally welcomed - although opposition politicians have promised to keep a watch on whether ACCAC's responsibilities become politicised.
ACCAC will follow ELWa, the post-16 education funding agency, into the Assembly government fold. However, the status of the Higher Education Funding Council for Wales remains unchanged.
John Valentine Williams, ACCAC's chief executive, has no plans to quit his post. He is not expecting job losses but is keen for the agency's new structure to be resolved as soon as possible.
"We have to work quickly to give assurances to staff as to where they are going to be in the new regime," he said.
Anna Brychan, director of the National Association of Head Teachers Cymru, said ACCAC's merger could benefit schools if it resulted in more coherent policies emerging from government.
But she added: "We would want to be certain that there continues to be a robust qualifications and assessment service."
Gethin Lewis, secretary of the National Union of Teachers Cymru, was concerned about the job security of ACCAC's 90-plus staff, but said: "We have confidence that the reasons for bringing ACCAC in-house are good. This is an important way to save money and ensure it goes to frontline services."
ACCAC's council had argued that it should stay outside of government. It raised particular concerns that the independence and "perceived credibility" of Wales's 104 exam-awarding bodies, including the Welsh Joint Education Committee, could be undermined if they were regulated directly by government.
"The current arm's length arrangements also protect government from any possible accusations of commissioning 'state textbooks', especially in sensitive areas such as history," it said in its submission to Mr Morgan.
"ACCAC's recognised and acknowledged independence is seen as beneficial. It also protects ministers from perceptions of excessive interference in areas which call for substantial professional inputs and judgements."
Opposition politicians broadly welcomed ACCAC's merger. Tory AM David Davies said: "We will be keeping a sharp eye to make sure education is not politicised."
Plaid Cymru AM Owen John Thomas said the move would make it easier to question ministers about ACCAC's work.