Does CPT code 51701 need to have a modifier attached?

Example 1: Patient with Medicare insurance has vulvar lesion with postmenopausal bleeding that is biopsied. Codes used were 99213-25, 51701, 56605-59, & 58100-59. For Number 3 Office Call, straight catheterization, biopsy of vulva, & Endometrial biopsy.

Example 2: Patient with BC/BS insurance comes in for urodynamics testing, no Office Call. Codes used were 51701, 51728, 51741, 51784, 51797. For straight catheterization, complex CMG with bladder voiding pressure, complex uroflow, EMG, abdominal pressure, add on code.

I did not use one because the CPT book does not list this code as a separate procedure and I used a 25 modifier on Example 1 for the Office Call. I’m getting more cofused the longer I look at this and try to figure out why. Please help!!

Thank you!