This report analyzes the City and County of San Francisco's (CCSF) future funding commitments to Caltrain over the next 10 years. It estimates total funding gaps of $145.8 million, including $40.1 million for Caltrain's electrification project, $41.7 million for ongoing capital projects, and $64.0 million or more for operating subsidies. The analysis also identifies risks that could increase CCSF's costs, such as potential cost increases for the electrification project and fluctuating revenues from sales tax. The report recommends steps to address the funding gaps and risks, including implementing a new operating subsidy formula tied to regional transportation goals and improving Caltrain's budgeting process.