Call your insurer or read the policy's territorial coverage section; don't rely on assumptions, because the answer varies wildly. Ask specifically: does the plan cover care outside the country at all, is it emergency-only or also routine care, what percentage is reimbursed, is there a different deductible abroad, must I pay upfront and claim later, is medical evacuation included, and are there trip-length limits after which coverage lapses. Get the answer in writing if you can.
Common limitations to expect: many national public health systems cover nothing or almost nothing abroad, with regional exceptions like reciprocal agreements between certain countries. Private plans often cover emergencies at out-of-network rates with high cost-sharing, exclude evacuation entirely, and reimburse at their home-country fee schedule, which can fall far short of foreign private hospital prices. Coverage also frequently ends once a stay abroad exceeds a defined duration, which matters for long-term travelers and new expats.