Allgery Code 95004 and Units

Hello,
I've been doing some research, and can't find the answer to this question...

Does CPT code 95004 have a maximum number of allowed units? We've been billing with 50 units and haven't had a problem with payment, but we would like to start billing 60 units. Is there a max number of units that can be billed?

Thanks so much!

Allgery Code 95004 and Units