I would code that as 33533 & 33517. I also found this from past searches.
This question came up back in 2012 about using Modifier 22 and I emailed Julie Painter at STS for clarification and received the following reply:
"It is not a given that the -22 modifier should be appended to the off-pump CABG cases. It would be determined on a case by case basis considering the work differential compared to the existing code. The entire global should be considered too, so maybe it takes a little longer to perform the procedure off-pump, but it might mean one less hospital or office visit during the global period.
There is no given formula or criteria for when to use the -22 modifier, but a general consideration is that the case should represent 20% - 30% more work then the procedure to report the -22 modifier, which will probably not typically occur in the off-pump versus on-pump CABG codes. Also, the -22 modifier takes into account the total work effort, so not only a time differential, but also increased intensity, technical difficulty of procedure, severity of the patient's condition, physical and mental effort required, risk to patient and physician. The op note should reflect the increased work involved and some payers require a separate note supporting the increased work effort.
So bottom line, there may be cases where the -22 modifier is warranted for an off-pump CABG case, but it should not be used on all cases."