In 2010, the Pew Center on the States contracted with WSIPP to augment its broader benefit-cost effort by focusing on criminal justice sentencing policies. The first task under the contract is to build a tool that analyzes adult sentencing policies and other crime-related public policies from a return-on-investment perspective. The second task is to apply the analytical framework to an evidence-based sentencing initiative underway in Washington State. The third task is to develop user-friendly software that will allow other States to use the sentencing tool in identifying policy options that can reduce crime and save money. The sentencing-related tool is being built to be part of the larger benefit-cost software WSIPP is developing. The current report focuses only on the sentencing-related application. The overall goal of the model is to estimate the net change in crime in a State, along with the net change in taxpayer spending linked to different mixes of incarceration and programming policies. Although at the time of the writing of this report (August 2010) there are no official proposals being considered in Washington State, for the purposes of illustration the new WSIPP model is used to estimate the crime and taxpayer effects of two example sentencing policies. One example reduces prison length of stay by 60 days for lower risk offenders whose current conviction is not a murder or sex offense. The second option example is to reduce prison length of stay by 60 days for all offenders sentenced to prison.