AbstractBackgroundIn people with cystic fibrosis (pwCF), the impact of cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapies, such as Elexacaftor–Tezacaftor–Ivacaftor (ETI), on structural changes in the lungs is unclear.ObjectiveTo determine the impact of ETI on clinical parameters and on structural lung disease as measured by the changes in the chest computed tomography (CT) scans in pwCF.MethodsPercent predicted forced expiratory volume in one second (ppFEV1), body mass index (BMI), and microbiologic data were collected at initiation and 3‐month intervals for 1 year. Chest CT scans before starting ETI therapy (baseline) and at 1‐year on ETI therapy were compared by two pulmonologists independently.ResultsThe sample size was 67 pwCF, 30 (44.8%) males, median age of 25 (16, 33.5) years. Significant increases in ppFEV1 and BMI observed by 3 months of ETI therapy persisted throughout 1 year of ETI therapy (p < 0.001 at all‐time points for both). After 1 year on ETI, pwCF had significant reductions in Pseudomonas aeruginosa (−42%) and MRSA (−42%) positivity. None of the pwCF had worsening of chest CT parameters during 1 year of ETI therapy. Comparing chest CT findings at baseline and at 1‐year follow‐up, bronchiectasis was present in 65 (97%) pwCF and at 1‐year follow‐up decreased in 7 (11%). Bronchial wall thickening 64 (97%), decreased in 53 (79%). Mucous plugging in 63 (96%), absent in 11 (17%), and decreased in 50 (77%). Hyperinflation/air trapping in 44 (67%), decreased in 11 (18%), absent in 27 (44%)ConclusionsETI significantly improved clinical outcomes and lung disease as documented by improvement in chest CT scans.