Haw. Rev. Stat. § 88-49: Employees paid partly from federal funds.

Where any employee, subject to the compensation law, has a portion of the employee's salary paid from federal funds but is not subject to the federal retirement system, the employee shall be entitled to all benefits and be required to make all employee contributions under the system based upon the full salary received by the employee, including that portion of the salary paid from federal funds.

This section shall be retroactive as to all employees affected, upon the employee paying into the system the contributions which would have been required had the employee's full salary been paid by the State or county, together with the necessary interest accumulations.