During COVID it was mandatory to have proof of health insurance. That is no longer the case, though you are advised to have medical insurance. The insurance should provide coverage for medical expenses and include hospital care, emergency treatment.
If you don't have medical insurance, it's not very expensive for a short trip, and it's absolutely worth considering. Aruba's hospitals and clinics don't accept Medicare or most US insurance plans, so you'll be paying out of pocket for any medical care. A comprehensive travel medical policy typically costs between $50-200 for a week-long trip, which is a small price compared to potential medical bills.
The good news is that Aruba has excellent medical facilities, including the modern Dr. Horacio E. Oduber Hospital in Oranjestad and several well-equipped clinics around the island. But here's the catch: they require payment upfront. Credit cards are accepted, but you'll need to pay and then seek reimbursement from your insurance company later. Having proper coverage means you can focus on getting better rather than worrying about how to pay for care.