N.H. Rev. Stat. Ann. § 77-A:3-a

In determining gross business profits before net operating loss and special deductions, a business organization shall calculate expense deductions as permitted under Section 179 of the Internal Revenue Code as provided in RSA 77-A:1, XX, except that for property placed in service on or after January 1, 2018, a business organization shall calculate expense deductions not to exceed $500,000.