Lung transplant is associated with a 60%-80% 1-year post-transplant readmission rate. Social contributors represent potentially modifiable risk factors for readmission. We compared the clinical and financial of implications of readmissions associated with and without social factors. Retrospective single-center study of lung transplant patients surviving to discharge between 2/2/2013 and 4/11/2023. Two reviewers categorized 1-year readmissions into two groups: social (eg, housing instability or rejection due to medication non-compliance) and non-social (eg, pancreatitis). Sociodemographics, transplant indications, Stanford Integrated Psychosocial Assessment for Transplant scores, lung allocation score, pre-operative hospitalization status, in-hospital post-operative course, and readmission costs were compared between patients with and without a social readmission. Among 192 transplants (109 double, 83 single), there were 436 1-year readmissions, including 33 social readmissions. Reviewer inter-rater reliability was >95% and Kappa was 0.91. A social readmission occurred in 21 (11%) patients, and 9 of these patients had multiple social readmissions. A social readmission was either the first or second readmission for 81% of these patients. Patients with a social readmission had a greater median number of readmissions (4 vs 2; p < 0.001) and were associated with longer length of stay (8 vs 5 days; p < 0.004), increased hospital costs ($23,813 vs $14,245; p = 0.04), and decreased margin (-$6145 vs $2287; p<0.001). Social readmissions represent a burden on patients and health systems. There is a strong association between social readmissions and increased costs, length of stay, and number of readmissions. Outpatient investment in patients with first-time social readmissions may improve outcomes and decrease healthcare costs.