(a) In case of impairment partial in character but permanent in quality, and not resulting in permanent total disability, the compensation is $177,000 multiplied by the employee's percentage of permanent impairment of the whole person. The percentage of permanent impairment of the whole person is the percentage of impairment to the particular body part, system, or function converted to the percentage of impairment to the whole person as provided under (b) of this section. The compensation is payable in a single lump sum, except as otherwise provided in AS 23.30.041, but the compensation may not be discounted for any present value considerations.
(b) All determinations of the existence and degree of permanent impairment shall be made strictly and solely under the whole person determination as set out in the American Medical Association Guides to the Evaluation of Permanent Impairment, except that an impairment rating may not be rounded to the next five percent. The board shall adopt a supplementary recognized schedule for injuries that cannot be rated by use of the American Medical Association Guides.
(c) The impairment rating determined under (a) of this section shall be reduced by a permanent impairment that existed before the compensable injury. If the combination of a prior impairment rating and a rating under (a) of this section would result in the employee being considered permanently totally disabled, the prior rating does not negate a finding of permanent total disability.
(d) When a new edition of the American Medical Association Guides described in (b) of this section is published, the board shall, not later than 90 days after the last day of the month in which the new edition is published, hold an open meeting under AS 44.62.310 to select the date on which the new edition will be used to make all determinations required under (b) of this section. The date selected by the board for using the new edition may not be later than 90 days after the last day of the month in which the new edition is published. After the meeting, the board shall issue a public notice announcing the date selected. The requirements of AS 44.62.010 - 44.62.300 do not apply to the selection or announcement of the date under this subsection.