Billing for one mbb (1/2 a facet joint)?

I did MBBs on a pt for the levels above and below a fusion (L1 and DPR L5). Did not do the MBB immediately adjacent to the pedicle with hardware, so basically I really just denervated 1/2 of two different facet joints... How do you guys bills this? My biller is telling me: 64493-50 64494-50 Does not seem correct? Thanks
Source: Student Doctor Network - Category: Universities & Medical Training Authors: Source Type: forums