Purpose of this study is to provide an estimate of concurrent enrollment (CE) costs and return on investment (ROI) in Colorado. This report is part of a larger U.S. Department of Education, Institute of Education Sciences (IES) funded grant to develop a college access and success research partnership (R305H170049). This study is of Colorado statewide CE programs created by House Bill 09-1319 and detailed in the CE Programs Act (C.R.S. §22-35-101 et seq.). The cost model describes a process creating a statewide estimate of CE economic costs using the ingredients method and flow of money to institutions of higher education (IHEs) to support CE. The financial returns model used the estimated impact of CE from a separate impact study to estimate the increases from CE participation in individual income, state and federal taxes, and the savings to some state and federal programs (Buckley, Pendergast, Klopfenstein, 2020). The cost model estimated the statewide economic cost of CE in 2016-17 was about $32 million for districts and $8 million for IHE. The IHE revenue that is explicitly targeted to pay for CE are Colorado Opportunity Fund payments estimated to be about $17 million, $36 million in tuition, and about $1 million in payments from districts for instructional services. IHE's then paid IHE about $26 million for instruction services by district personnel. The impact study estimated CE increased college matriculation and post-secondary completion for a sample of CE students. This sample was created to support a rigorous evaluation and had above average reading scores. The returns estimate for a similar group of 16,965 CE students would see an increase in post-secondary completers of 4,094 students. These completers generate an estimated lifetime increase in income of $2,890 million, state government taxes and savings of $274 million, and federal taxes and savings of $472 million. The lifetime ROI for the returns sample for Colorado (which made the CE investment) is estimated to be over 600%. This indicates that CE is a good investment for Colorado. [The report was produced by Augenblick, Palaich and Associates.]