The approval and subsequent reimbursement of CFTR modulator therapies from 2012 have provided a potential "game-changing" treatment for patients with cystic fibrosis (CF), especially among younger patients. We used HCUP-NIS and HCUP-KID data in 2006, 2009, 2012 and 2016 to compare the number of admissions, hospital charges/cost, length of stay (LOS) and other clinical outcomes between inpatient admissions aged over and below 20 with CF before and after the approval of CFTR therapies. We found the number of hospitalizations with CF dropped among those aged 0-20 but increased among those aged over 20. We found the average LOS and charges/costs increased among the former and decreased among the later. These findings support the hypothesis that modulator therapies have impacted on patterns of hospital care, contributing to a reduction in the number of young people treated in hospital albeit with an increase in their complexity relative to those aged over 20.