P.M. Lattner Manufacturing Co. and Accident Fund General Insurance Co. v. Michael Rife, 2 N.W.3d 859

Michael Rife, a welder, previously suffered a right shoulder injury in 2009 at P.M. Lattner Manufacturing and settled via a commutation agreement, receiving compensation based on industrial disability (loss of earning capacity).
In 2018, Rife sustained a second right shoulder injury at the same employer and sought workers' compensation benefits.
The legal landscape shifted between the injuries: pre-2017, shoulder injuries were non-scheduled and compensated by industrial disability; post-2017 amendments, such injuries were scheduled and compensated based on functional impairment (percentage of loss of use).
The workers’ compensation commissioner awarded Rife permanent partial disability benefits for the 2018 injury and ordered reimbursement for costs of an independent medical examination (IME).
On appeal, the district court disagreed on apportionment and IME reimbursement; the court of appeals partially affirmed/reversed, raising issues of benefit calculation and recoverable IME costs.
The Iowa Supreme Court addressed the proper method of apportioning liability for successive injuries under changed compensation systems and the extent of IME expense reimbursement.

Issue	Rife's Argument	P.M. Lattner's Argument	Held
How to apportion disability benefits for successive injuries under different compensation methods	Apportionment should not occur because the statute does not specify a method, and two injuries were compensated under different measures	Employer is entitled to credit for prior compensation, offsetting the second injury benefits entirely	Employer gets credit only for prior functional impairment, not for broader industrial disability; remanded to determine the correct amount
Reimbursement for IME expenses	Entitled to reasonable costs for the full examination related to the impairment rating	Not entitled to reimbursement or only limited to the cost of the impairment rating itself	Entitled to reimbursement for all reasonable IME expenses related to the impairment rating, not only the rating cost

Sherman v. Pella Corp., 576 N.W.2d 312 (Iowa 1998) (explains industrial disability method and compensation based on earning capacity)
Second Inj. Fund of Iowa v. Shank, 516 N.W.2d 808 (Iowa 1994) (industrial disability includes loss of earning capacity, not just functional impairment)
Mortimer v. Fruehauf Corp., 502 N.W.2d 12 (Iowa 1993) (industrial method measures actual reduction in earning potential)
Warren Properties v. Stewart, 864 N.W.2d 307 (Iowa 2015) (lack of apportionment method in statute doesn't bar application of apportionment)
Waldinger Corp. v. Mettler, 817 N.W.2d 1 (Iowa 2012) (court does not defer to the commissioner's interpretation of workers' comp statutes)
Floyd v. Quaker Oats, 646 N.W.2d 105 (Iowa 2002) (agency determination of impairment vs. aggravation is fact-based)
Coffey v. Mid Seven Transp. Co., 831 N.W.2d 81 (Iowa 2013) (standard governing judicial review of agency decisions)
NextEra Energy Res. LLC v. Iowa Utils. Bd., 815 N.W.2d 30 (Iowa 2012) (review standard for agency statutory interpretation)