We do a number of ureteral stent exchanges in our ASC. The ICD-10 diagnoses I assign are T19.1XXA, Z46.6 with the 3rd one being the reason for the stent to begin with … with hydronephrosis being the most common. My question is two-fold.

1. Does it matter what sequence the codes are in?
2. For those patients that have the stent permanently and return for an exchange every 6 months or so…should the 7 character to a D?

Thanks for any assistance you can provide.