First you need to find out if the payer or carrier has any guidelines on what code to use (many do). If so, you should follow those guidelines. If not, this is what I've found:
1. CMS currently does not have a written directive on what CPT code to use for balloon sinuplasty.
2. There is not an industry standard on what CPT code to use.
3.AAO-HNS official position is that under specific circumstances certain current FESS codes can be used. See cohttp://www.entnet.org/Practice/Coding-for-Sinus-Balloon-Catheterization.cfm
4. If you are billing the facility component HCPCS code for cathether C1726. Medicare payment indicator for this is "N1" which means it's a packaged item, no separate payment made.
Hope this helps.