If it is past 6 years on a Medical debt and under 15000 do you have to pay or not?

Check your sates SOL on certain debts, if it is SOL for legal recourse, than some people do choose to walk away, just because you can't be sued and it will be dropping off of your reports doesn't mean they won't stop collection efforts unless you send a C&D letter which i would do especially if it met the criteria I described.