CFTR (cystic fibrosis transmembrane conductance regulator) modulators are small molecules that directly change the CFTR protein, improving function of the CFTR chloride channel. Beginning in 2012 with the FDA approval of the first CFTR modulator, ivacaftor, this class of medication has had largely positive effects on many outcomes in people with cystic fibrosis (pwCF), including lung function, quality of life, and growth. There have been continued exciting developments in the current research on CFTR modulators, expanding beyond original studies. This first part of a three-part Cystic Fibrosis (CF) Year in Review 2020 will focus on research on CFTR modulators. Subsequent parts of the CF year in review will cover pulmonary and infectious inflammatory aspects, and the multisystem effects of CF in the 2020 literature. The review focuses on articles from Pediatric Pulmonology, but it includes articles from other journals that are of particular interest to clinicians. New developments in CF research continue to be brought forth to the CF community, deepening the understanding of this disease and improving clinical care.