From southwest.com:

Chicago/O'Hare, IL (ORD) and Washington/Dulles, DC (IAD) End of Service

Southwest Airlines will no longer operate service to, from, or through Chicago/O'Hare, IL (ORD) and Washington/Dulles, DC (IAD) beginning June 4, 2026. If you have existing travel booked that includes Chicago/O'Hare, IL (ORD) or Washington/Dulles, DC (IAD) on or after this date, your reservation will be affected.

Option 1: You can keep your existing reservation for travel on or before June 3, 2026.

Flights operating before the end of service date will not be impacted. Customers traveling prior to June 4 do not need to take additional action.

Option 2: Rebooking eligibility

Customers holding reservations to, from, or through Chicago/O'Hare, IL (ORD) or Washington/Dulles, DC (IAD) for travel on or after June 4, 2026 may rebook or travel standby (within 14 days of their original date of travel to, from, or through the available alternate airports without paying a change in airfare).

Applicable alternate stations:

• Chicago/O'Hare, IL (ORD): Chicago/Midway, IL (MDW), Milwaukee, WI (MKE), Indianapolis, IN (IND)
• Washington/Dulles, DC (IAD): Washington/Reagan, DC (DCA), Baltimore, MD (BWI), Philadelphia, PA (PHL), Richmond, VA (RIC)

Option 3: Refund eligibility

If your reservation includes Chicago/O'Hare, IL (ORD) or Washington/Dulles, DC (IAD) on or after June 4, 2026, you are eligible for a refund for:

• the unused ticket (even if your ticket was non-refundable); and
• any optional travel charges (such as an Extra Legroom seat or Priority Boarding) you paid for the flight(s) on which you don’t travel.