This is a prospective, single-center, nonrandomized observational study to investigate the utility of urine lipoarabinomannan (LAM) as a test to identify individuals at very low risk for having a sputum culture positive for Nontuberculous Mycobacteria (NTM). The study is designed to evaluate if a urine test can eliminate the need for obtaining a sputum specimen to screen for NTM in individuals with Cystic Fibrosis (CF). The participants will be asked to provide 3 urine samples either in person or by mail over approximately 3 years. The 3 urine sample requests will be timed to coincide with their usual clinical care and routine sputum collection.

Inclusion Criteria:

• Informed consent obtained online or in person from the participant
• Enrolled in the CFF Patient Registry (CFFPR)
• Be willing and able to adhere to study procedures in the context of clinical care, and other protocol requirements
• Diagnosis of CF consistent with the 2017 CFF Guidelines NTM culture status of negative (defined by a review of clinical and culture data with at least 3 years of clinical data available to review and at least one negative culture within the year prior to enrollment and no known history of previous positive cultures for pathogenic NTM)

Exclusion Criteria:

1. Has any other condition that, in the opinion of the Site Investigator/designee, would preclude informed consent or assent, make study participation unsafe, complicate interpretation of study outcome data, or otherwise interfere with achieving the study objectives

100 adult male or female participants with a diagnosis of CF and NTM culture status of negative and no known previous positive cultures for pathogenetic NTM