22551 for 1st level fusion (C3-C4), 22552 for C4-5 level & 22552 for C5-6 level. Instrumentation - 22846 (4-7 vertebral SEGMENTS). The fusion goes by LEVEL, the instrumentation is by SEGMENT. In this case there are 3 levels, but there are 4 segments (C3, C4, C5, C6) that the instrumentation would be attached to. Also, if your surgeon uses cages, you would use 22851 for each level. Also, if the instrumentation (i.e., plate) is an integral part of the cage and not a separate construct, you would only bill the 22851 for each level there's a cage, & you wouldn't bill the instrumentation code. That's the way I understand it. If anyone disagrees, let me know, please.