N.H. Rev. Stat. Ann. § 228:115

Any contract for public-private design-build-finance-operate-maintain or design-build-operate-maintain services shall provide for securing and maintaining a liability insurance policy for contractors and engineers in the design phase of a project which shall be limited to 10 percent of the cost of such project. A certificate of liability compliance shall be included in the bid. Any such contract shall require a bond under RSA 447:16 for the design-build and bonds, letters of credit, or other forms of security for the operations and maintenance phases of the project.