Employee fell & injured EE's shoulder while bolting on 3/19 but didn't report injury until 3/24. EE was seen by local ER dr. & continued working until follow-up appt. on 3/31. EE was placed on modified duty on 3/31 pending an MRI. EE was seen by an ortho dr. on 4/22 & it was determined EE would need surgery. This will be a charge back incident with first reported day missed 4/1.