I have Tricare For LIfe and Medicare. On a 7-night cruise out of Miami on RCL Oasis of the Seas in December, I fell (while in Philipsburg, St Maarten) and fractured my wrist. Long story short, I didn't want to go to the ER on St Maarten, so got back on the ship and went to the Medical Center the next morning (after icing, ibuprofen, and no improvement). I had purchased Travel Insurance through Travelex, and since it was the primary payer, I didn't even bother with Medicare or TFL; just paid the (actually very reasonable) charge of $560 via my credit card, and then put in for reimbursement, which was done very quickly through their Travelon app. My recommendation? Pick up travel insurance but make sure it's primary rather than secondary.