N.H. Rev. Stat. § 21-G:25

Volunteer service shall not be used, directly or indirectly, for personal financial gain, or to facilitate non-public communications with executive branch officials or classified employees for the purpose of promoting or advancing any matter on behalf of a third party, or to influence executive branch officials or classified employees in the performance of their duties. In furtherance of this prohibition: I. No person shall serve as a public employee, as defined by RSA 15-B:2, VIII, or serve as an appointee or volunteer for any multi-branch commission, committee, board, or similar governmental entity, and simultaneously be a person who has a duty to register as a lobbyist pursuant to RSA 15, or is employed by, or maintains an ownership interest in, any entity which employs a registered lobbyist. II. No person shall serve as a public employee in a position that establishes policy or adjudicates matters before any agency while maintaining any ownership interest in, or being employed by, any entity, engaged in promoting or opposing, directly or indirectly, any legislation pending or proposed before the general court, or promoting or opposing any action or inaction on any matter, contract, license, permit, or administrative rule, proposed or pending, before the executive branch. III. Unless otherwise prohibited by law, the prohibitions of RSA 21-G:25, I and II, shall not apply to: (a) Appearances before the courts or any adjudicative proceedings, or non-adjudicative processes, as defined by RSA 541-A; (b) Service in a position subject to appointment by the governor and council; (c) Testimony or participation in any public meeting, or service on any commission, committee, board, panel, or other similar governmental entity that is subject to the public meeting and notice requirements of RSA 91-A, or the public right of access mandated by part 1, article 8 of the New Hampshire constitution. (d) Volunteer public service related entirely to a ceremonial, celebratory, historical, or recreational program or event; public health or safety incident or drill, or consumer protection assistance; (e) Ownership of publicly-traded stock; or (f) A public employee, appointee, or volunteer's personal application for any license, permit, or ruling from a state agency.