Remote Sputum Collection in Cystic Fibrosis

Inclusion Criteria: * People with a diagnosis of cystic fibrosis (CF) based on CF Foundation (CFF) guidelines. The CFF guidelines consider a diagnosis of CF based on: (1) two known disease-causing CFTR mutations (based on historical genetic testing in clinical documentation or PortCF, the CFF patient registry), OR (2) sweat chloride 60 mmol/L (based on historical sweat chloride testing in clinical documentation or PortCF) and phenotypic findings consistent with cystic fibrosis in more than one organ system, OR (3) CFF accredited center physician diagnosis, based on clinical manifestations in the absence of two CFTR mutations with full gene mapping (based on historical genetic testing in clinical documentation or PortCF). * Age 18 years old or greater * People with the ability to comply with study visits and study procedures as judged by the investigator. Exclusion Criteria: * Solid organ transplant recipients, given the presence of immunosuppression. * Those who are unable to tolerate sputum induction (hypertonic saline) or the inability to attempt sputum expectoration. * Subjects who do not have access to a FedEx location or pick-up services will be excluded.