If you are a US citizen and plan for healthcare expenses in retirement, you could have stashed more than 4 million baht in an HSA, tax-free, for over a decade. The money in the HSA is investable in any form, like buying index funds, etc., and you can use their VISA or MC to pay for all your medical expenses. All my friends have HSA cards in the US. I have one stashed with money that earned 24% last year alone. I used it twice at Bangkok Hospital, Pattaya. Besides, I have credit cards, each with a credit limit close to one million baht. Hopefully, I can survive an emergency in Thailand.