I am writing you not because I have the answer to your question but because I am having issues of my own regarding PHP claims. I cannot seem to get them right. I am trying to figure out what the difference is between PHP and IOP claims? Are you using modifiers with your HCPCS code? I keep getting mine kicked back and denied for lack of information between boxes 42-49. Not sure where the problem is. If you know any information about this it would be very much appreciated. Thank you!!