MY SURGERY IS OUT OF STAT...

MY SURGERY IS OUT OF STATE. THE INSURANCE -GREATWEST-HEALTHLINK-, SAY THAT THEY WILL ONLY PAY 70% OF THE COST . I WAS WONDERING IF ANYONE KNOWS HOW OR IF I CAN GET MORE IF THE COST COVERED BY MY INSURANCE? THE DOCTERS IN MY STATE-MO.- HAD NO OPENINGS UNTIL ONE YEAR LATER ;BUT BY THEN ALL PRE -OP TESTING WOULD HAVE HAD TO BE REDONE. IN MO. THEY WOULD HAVE PAID 90%. HAS ANYONE EVER HAD THIS HAPPEN TO THEM? JUST THOUGHT I WOULD ASK. BEEN THINKING ABOUT IT.