While these are exciting times for the cystic fibrosis (CF) community with personalized, mutation-specific CFTR modulator treatments now available, it is unclear if the uncommon yet growing adult-diagnosed CF population also stand to benefit. These patients are older and have unique challenges, issues, and health care needs. There is considerable phenotypic and genotypic heterogeneity in this group, with many having atypical mutations. It is unknown how many adult-diagnosed CF patients are eligible for these breakthrough therapies based on their genotype. Using available product monographs, we find that the majority of the adult-diagnosed CF population (83%) is eligible for currently-approved CFTR modulator therapies.