Purpose of Review <p>As the volume of lung transplants performed worldwide continues to increase, the need for noninvasive biomarkers to monitor the allograft and support optimal patient care has become increasingly apparent. We reviewed existing literature and propose a strategy for utilizing this test in clinical practice.</p> Recent Findings <p>Advances in technology to monitor donor-derived cell free DNA (dd-cfDNA) in solid organ transplant have resulted in numerous recent studies evaluating this test as a biomarker in lung transplant. These studies consistently demonstrate elevations in dd-cfDNA are present in the setting of tissue damage to the allograft. How we should be incorporating these results into our clinical care algorithms remains uncertain.</p> Summary <p>Donor-derived cell free DNA has been consistently demonstrated to correlate with allograft dysfunction and injury and may provide a non-invasive test to aid in monitoring allograft health. Ongoing challenges include understanding appropriate interpretation and limitations of testing.</p>