Cystic fibrosis (CF) is a genetic disease caused by mutations in the CF transmembrane conductance regulator (CFTR) gene, resulting in chronic bacterial lung infections and tissue damage. CF macrophages exhibit reduced bacterial killing and increased inflammatory signaling. Iron is elevated in the CF lung and is a critical nutrient for bacteria, including the common CF pathogen Pseudomonas aeruginosa (Pa). While macrophages are a key regulatory component of extracellular iron, iron metabolism has yet to be characterized in human CF macrophages. Secreted and total protein levels were analyzed in non-CF and F508del/F508del CF monocyte derived macrophages (MDMs) with and without clinically approved CFTR modulators ivacaftor/lumacaftor. CF macrophage transferrin receptor 1 (TfR1) was reduced with ivacaftor/lumacaftor treatment. When activated with LPS, CF macrophage expressed reduced ferroportin (Fpn). After the addition of exogenous iron, total iron was elevated in conditioned media from CF MDMs and reduced in conditioned media from ivacaftor/ lumacaftor treated CF MDMs. Pa biofilm formation and viability were elevated in conditioned media from CF MDMs and biofilm formation was reduced in the presence of conditioned media from ivacaftor/lumacaftor treated CF MDMs. Defects in iron metabolism observed in this study may inform host-pathogen interactions between CF macrophages and Pa. Cystic fibrosis (CF) is a genetic disease that afflicts approximately 31,000 people in the United States, with a median predicted survival of 47.4 years for those born in 2018 (CF Foundation Registry Annual Report, 2018). CF is caused by mutations in the CF transmembrane conductance regulator (CFTR) gene, a chloride and bicarbonate channel that regulates epithelial anion transport 1. While over 1,800 CFTR mutations have been identified, the F508del mutation is the most prevalent: 44.2% of the population is F508del homozygous (CF Foundation Registry Annual Report, 2018). Defective chloride and bicarbonate secretion, coupled with continued absorption of sodium by the epithelial sodium channel (ENaC), facilitates an accumulation of dehydrated mucous in the airway. Bicarbonate aids in the maintenance of airway pH and facilitates antimicrobial peptide function 2 , and disruption of bicarbonate contributes to airway acidification and reduced bacterial clearance in CFTR knockout pigs 3. Additionally, increased mucin content is associated with neutrophil recruitment and inflammatory markers in the bronchoalveolar lavage of young children with CF 4 and CFTR knockout ferrets 5. These changes in airway pH, bacterial clearance, and inflammatory milieu facilitate chronic lung disease and bacterial infection over the lifetime of the CF patient 6. One of the most common and deleterious opportunistic pathogens that colonize the adult CF lung is Pseudomonas aeruginosa (Pa) 7-9. As of 2018, 45.3% of CF subjects in the United States were reported to have Pa cultured from their sputum and 16.9% of CF subjects with a Pa infection were positive for multidrug-res...