Patients with gastrointestinal cancer face significant insurance instability that impacts surgery timelines and costs.

• 9.8% of GI cancer patients changed insurance within a year post-diagnosis, compared to 8.8% of controls (adjusted HR 1.18).
• Insurance instability led to delayed surgeries (adjusted rate ratio 1.15) and higher out-of-pocket costs ($3,675 vs $3,206).

Employment disruptions accounted for 97.2% of insurance instability, emphasizing the need for policies to ensure job and coverage security during cancer treatment.

• Risk was highest for patients with HMO (HR 2.60) and comprehensive plans (HR 2.66).