Hi bizmatics,
If your documentation supports billing both codes, yes you may and no modifier is necessary reviewing Charge Assist. There was also an article I found from CPT Assistant that may help ....... "Time-based codes accumulation of incremental intervals of time, clarification, CPT Assistant, March 2014, Page 15, Category: Frequently Asked Questions".
Thanks for listening,
Dana Chock, RHIT, CPC, CANPC, CHONC, CPMA, CPB