Hawaii Revised Statutes Division 2. Business § 431:10A-304

(a) No medicare supplement policy or certificate in force in the State shall contain benefits that duplicate benefits provided by medicare.

(b) The commissioner shall adopt reasonable rules to establish specific standards for the provisions of medicare supplement policies and certificates. The standards shall be in addition to and in accordance with applicable laws of this State, including the provisions of part I of this article. No requirement of this chapter relating to minimum required policy benefits, other than the minimum standards contained in this part, shall apply to medicare supplement policies and certificates. The standards may cover, but shall not be limited to:

(c) The commissioner may adopt reasonable rules that specify prohibited policy provisions not otherwise specifically authorized by law, which, in the opinion of the commissioner, are unjust, unfair, or unfairly discriminatory to any person insured or proposed to be insured under any medicare supplement policy or certificate.

(d) A medicare supplement policy or certificate shall not exclude or limit benefits for losses incurred more than six months after the effective date of coverage because it involved a preexisting condition. The policy or certificate shall not define a preexisting condition more restrictively than a condition for which medical advice was given or treatment was recommended by or received from a physician within six months before the effective date of coverage.