Hawaii Revised Statutes
236D. Estate and Transfer Tax
236D-2.3 Effect of civil union.

§236D-2.3 Effect of civil union. All provisions of the Internal Revenue Code referred to in this chapter that apply to a husband and wife, spouses, or person in a legal marital relationship shall be deemed to apply in this chapter to partners in a civil union with the same force and effect as if they were "husband and wife", "spouses", or other terms that describe persons in a legal marital relationship. [L 2011, c 1, §5]
Attorney General Opinions
Civil union partners have all the same rights, benefits, protections, and responsibilities under the law as married couples who are of the opposite gender; civil union partners have the same tax filing status options as married couples who are of the opposite gender for Hawaii income tax purposes for taxable years beginning after December 31, 2011. Att. Gen. Op. 11-2.