Continuity of coverage for overseas workers returning home?

I am a U.S. native who has been working in South Korea as a teacher for about 2 1/2 years. My health insurance here is covered by the national health insurance, and I have had continuous coverage under that since coming here. A year ago, while working here, I was diagnosed with chronic leukemia. The government health insurance here covers my medication, but I want to go back to America next year. If I bring my documentation from Korea that shows that my coverage has been continuous since pre-diagnosis, will that be enough to show continuity of coverage so I can get insured when I get back? Is there any advice about this?