ABSTRACT Aim This study investigates the impact of hospital length of stay (LOS) on 30-day readmissions for Chronic Obstructive Pulmonary Disease (COPD) patients using a U.S. national dataset. It also aims to understand how discharge dispositions influence LOS and readmission risk trends and to offer valuable insights into the effectiveness of post-discharge care and its role in readmission outcomes. Methods Given the complexities of the relationship between LOS and readmissions, we employ instrumental variable (IV) analysis to mitigate potential biases. Our data cover 11 years to ensure the study's robustness and comprehensiveness. Results Our findings reveal that older, Medicare-insured patients, predominantly discharged routinely, constitute a significant portion of readmitted cases. Data visualization shows increasing readmission rates with extended LOS, particularly among patients discharged against medical advice. However, IV analysis indicates that longer LOS is associated with reduced readmission rates. Conclusions This study shows the critical role of insurance type, socio-economic factors, and hospital characteristics in determining both readmission rates and LOS among COPD patients. The results highlight the necessity for targeted interventions to reduce healthcare disparities, especially for Medicare and Medicaid beneficiaries. This study provides valuable insights for improving COPD patient care and addressing disparities in healthcare access and outcomes.