Without knowing more about the circumstances that pre-empted the tubal procedure completion, a modifier 53 may not be correct. Here's a quote from another post that you may want to consider before determining whether to use a 53 or 52:
"CPT Assistant December 1996 explains you should use modifier 53 when a patient experiences an unexpected response or life-threatening condition that causes the procedure to be terminated (such as the patient fainting or developing an arrhythmia)......Payers will reduce the allowable when this modifier is appended. For instance, Tufts Health Plan will reimburse only 20 percent of the allowable amount, while Harvard Pilgrim will allow 50 percent of the allowable......Unlike modifier 53, modifier 52 implies the physician did at least some of the work involved in doing the procedure. In most cases, the amount of the reduction is dependent on documentation showing how much work was involved. In some cases, if the insertion attempt involved more significant work than normal placement, no reduction in payment will occur. For instance, in this case, the patient had a false track, but many insertions that involve cervical stenosis can be equally as difficult. Tufts indicates you would receive 70 percent or more of the allowable when you report a modifier 52."
(Of course, modifier choice may be moot for a tubal on a Medicare patient, but I still thought it worth mentioning.)
Becky, CPC