On July 26, 2017, California Governor Jerry Brown signed into law a bipartisan bill that extends the state’s cap-and-trade program to 2030. Cap and trade is a key part of California’s plan to reduce greenhouse gas emissions 40 percent below 1990 levels by 2030. The enacted bill makes design changes to the post-2020 carbon market, such as including a price ceiling, price containment points, additional limits to the number and location of offset credits, limits on who can set greenhouse gas emission requirements, and specifics on industry assistance factors. This document summarizes these program changes.