Some employers are implementing reference-pricing benefit designs, which establish limits on the amount they will pay for some procedures covered by employer-sponsored insurance. Employees are required to pay the difference between the employer’s contribution limit and the actual price received by the hospital. These initiatives encourage patients to select low-price facilities and indirectly encourage facilities to reduce prices to increase patient volume. We evaluated the impact of reference pricing on the use of and prices paid for knee and hip replacement surgery by members of the California Public Employees’ Retirement System (CalPERS) from 2008 to 2012, using enrollees in Anthem Blue Cross as a comparison group. In the first year after implementation, surgical volumes for CalPERS members increased by 21.2 percent at low-price facilities and decreased by 34.3 percent at high-price facilities. Prices charged to CalPERS members declined by 5.6 percent at low-price facilities and by 34.3 percent at high-price facilities. Our analysis indicates that in 2011 reference pricing accounted for $2.8 million in savings for CalPERS and $0.3 million in lower cost sharing for CalPERS members.