DEPARTMENT OF LABOR AND EMPLOYMENT
Division of Workers’ Compensation
7 ccr 1101-3
WORKERS’ COMPENSATION RULES OF PROCEDURE

Rule  12	Permanent Impairment Rating Guidelines

Rule 	12-3	APPORTIONMENT

(A)	For claims with a date of injury prior to July 1, 2008, a Level II accredited physician (“the Physician”) shall apportion any preexisting medical impairment, whether work-related or non work-related, from a work-related injury or occupational disease using the AMA Guides, 3rd Edition, Revised, where medical records or other objective evidence substantiate a preexisting impairment to the same body part.  Any such apportionment shall be made by subtracting from the injured worker’s impairment the preexisting impairment as it existed at the time of the subsequent injury or occupational disease.  The physician shall explain in their written report the basis of any apportionment.  If there is insufficient information to measure the change accurately, the physician shall not apportion.

(B)	For claims with a date of injury on or after July 1, 2008, the Physician may provide an opinion on apportionment for any preexisting work related or non work- related permanent impairment to the same body part using the AMA Guides, 3rd Edition, Revised, where medical records or other objective evidence substantiate a preexisting impairment.  Any such apportionment shall be made by subtracting from the injured worker’s impairment the preexisting impairment as it existed at the time of the subsequent injury or occupational disease.  The Physician shall explain in their written report the basis of any apportionment. If there is insufficient information to measure the change accurately, the Physician shall not apportion. If the Physician apportions based on a prior non work-related impairment, the Physician must provide an opinion as to whether the previous medical impairment was identified, treated and independently disabling at the time of the work-related injury that is being rated.  Identified and treated in this context requires facts reflecting that a medical provider previously noted and provided some level of treatment for the non work-related impairment.

(1)	The effect of the Physician’s apportionment determination is limited to the provisions in section 8-42-104.  When filing an admission an insurer shall provide documentation reflecting compliance with section 8-42-104.         

(2)	If the Physician provides an opinion on the apportionment of medical and temporary disability benefits, the claimant’s receipt of medical and temporary disability benefits shall not be reduced based upon any such opinion.