Billed a hospice claim NOE in september 2014 for a 90 day cert period found out later that the patient had done used her two 90 day cert periods with another hospice re filled an NOE in December (after the 90 days) for the 60 day cert period. Backed up and re funded the pervious paid claims before the December NOE. Now the NOE for this one in December was filled timely and is getting denied saying needs KX modifer and occurance span 77 with dates, what does this mean and what would the date span be. I am new to billing hospice so any help would be great.