CONCORD, N.H. — A consultant who helped Arkansas obtain federal permission to expand Medicaid to its poor adults by using private insurance says New Hampshire needs more time before adopting a similar approach.

Richard Albertoni of Public Consulting Group told the House Finance Committee on Wednesday that if New Hampshire adopts too ambitious an implementation timeline there might not be enough insurance companies offering products to provide competition.

Albertoni, who is advising the state Insurance Department, said using the exchange for newly eligible adults under an expansion of Medicaid in 2015 would pose significant risks to its success. Insurance officials say they don't know of any companies planning on joining Anthem Blue Cross and Blue Shield as a provider on the exchange. They say more providers are needed to adopt an Arkansas model.