As a complementary effort to the annual “2021 State of Open at the University of Colorado Boulder” report, this special report provides a deeper look at article processing charges (APCs) for open access (OA) articles published by authors at the University of Colorado Boulder (CU Boulder). This analysis is not intended to be updated regularly, which is why it is being presented separately from the larger report. This special report utilizes Dimensions as a data source for OA articles published by CU Boulder authors in 2020. When cross-referenced with journal-level APC data from the Directory of Open Access Journals (DOAJ), the Dimensions data can be used to estimate total costs of APCs for applicable CU Boulder articles from 2020 as well as the estimated percentage of APCs covered by the CU Boulder Libraries OA Fund.