First, when billing an any x-ray for a SNF patient you need to apply to -26 modifier to the procedure code and ONLY if your office pays your x-ray technician and owns the equipment, can should you bill the -TC modifier with the procedure code directly to the SNF.
Regarding the denial for the J3301, it also sounds to me that this denial may be tied to the 5010 edits. We too are having trouble with our claims getting to Medicare, but this is due to our software not being 5010 compliant. Good news is our update is coming next week!
I would double check with your Clearinghouse to see what rejection they are receiving on their end. They should definitely be able to tell you!
Hope this helps!
** I also posted a question yesterday regarding "New Patient Consults" would love to have to look for that and what your opinion is! **