N.H. Rev. Stat. § 604-A:6
In any criminal case in which counsel has been appointed to represent a defendant who is financially unable to obtain investigative, expert or other services necessary to an adequate defense in his case, counsel may apply therefor to the court, and, upon finding that such services are necessary and that the defendant is financially unable to obtain them, the court shall authorize counsel to obtain the necessary services on behalf of the defendant. The court may, in the interests of justice and upon finding that timely procurement of necessary services could not await prior authorization, ratify and approve such services after they have been obtained. The court shall determine reasonable compensation for the services and direct payment upon the filing of a claim for compensation supported by an affidavit specifying the time expended, the nature of the services rendered, the expenses incurred on behalf of the defendant, and the compensation, if any, received in the same case for the same services from any other source. The compensation to be paid to any person or association for such services shall not exceed $300 unless the court determines that the nature or quantity of such services reasonably merits greater compensation. The $300 limit for compensation shall not include or apply to reimbursement for expenses reasonably incurred. In any case in which appointed counsel seeks funds for services other than counsel under this section, the application for such funds may be filed with the court on an ex parte basis and may, upon the request of appointed counsel, be sealed until the conclusion of the representation.
RSA 604-A:6
1965, 296:1. 1983, 321:1. 1989, 188:1, eff. Jan. 1, 1990. 2005, 135:1, eff. Jan. 1, 2006.