# using mod GA vs GX when billing Medicare



## nikkiwel79 (Jul 10, 2012)

I have used modifier GX on an L code to Medicare knowing that the procedure would deny.  I was expecting that the denial would hold pt responsible however it rejected the same way it would have without the modifier (contractual obligation); will the GX modifier affect my claim if a 2ndary payor is involved?  Will they consider and pay?  Ultimately we do have an ABN on file and can bill the pt as it was a voluntary signing of the ABN by the pt...


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## Lujanwj (Jul 17, 2012)

Attached is MLN Matters MM6563.  Explains the modifiers and their usage pretty well; however, it doesn't include payment info.

Hope it helps


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