At Baltimore Washington International Thurgood Marshall Airport (BWI), Spirit Airlines BWI Terminal is based in Concourse D. Travelers can utilize self-service kiosks, check in at Zone D, and pass through several security checkpoints. To ensure easy boarding, arrive early Spirit recommends arriving at least two hours before domestic flights and three hours before international ones. Learn about Spirit’s luggage policies, which include costs for checked and carry-on items. To save money, think about booking your seats in advance online. There are food options on Concourse D, and BWI offers free WiFi throughout the terminal for internet access.