Podiatry Coding & Billing Alert

Question: I’ve begun a small rural clinic and am taking over a lot of the coding responsibilities, but I’m having trouble understanding ICD-10. I billed S90.45xA (Superficial foreign body … initial encounter) and it was rejected for a patient I saw presenting a contusion to the great toenail, left foot. I keep having problems understanding the right way to use the x character. What did I do wrong?

Illinois Subscriber

Answer: Let’s talk about the code selection first. You said you treated a contusion that included damage to the nail, so that would be coded S90.211A (Contusion of right great toe with damage to nail, initial encounter). But you used a code for superficial foreign body in the toe, rather than for a contusion.

Now, if the patient presented with a superficial foreign body of the right great toe, active care encounter, you would have coded S90.451A. It should be appropriate for the treatment of a contusion right great toe with damaged nail.

And you would not have used the x as there, because the -1 character there in the sixth spot indicates location. The x is used only as a place marker when there are no character choices listed for the sixth spot when a seventh is required. There are some codes that use more than one x as place markers, so take care with your coding research.