Hi mcquinn9911!

The diagnosis pointer (box 24E on the CMS1500 claim form) actually refers to which the field the diagnosis code that applies to that procedure is listed in box 21 of the claim form.

Box 21, where the diagnosis code or codes are listed has room for up to 12 diagnosis codes. The fields are labeled A, B, C, D...... etc.

So, for example, if you only have 1 diagnosis code in box 21 of the claim form, the diagnosis pointer in box 24E would simply be "A". If you have 2 diagnosis codes listed in box 21 and both apply to the server, your diagnosis codes would be "AB". If you have three and all apply, your diagnosis pointer would be "ABC".....and so on and so forth.

Now, as far as what diagnosis code(s) should be listed in box 21 - that all depends on the patient! Of course, not every patient will have the same diagnosis or diagnoses, so the diagnosis or diagnoses your dentist has deemed appropriate for that patient's condition/symptoms should go in box 21.

Here are a few examples of commonly used ICD-10 diagnosis codes used for a biopsy, vestibule of the mouth:

C06.1 - Malignant neoplasm of vestibule of mouth
D10.39 - Benign neoplasm of other parts of mouth
D37.0 - Neoplasm of uncertain behavior of lip, oral cavity and pharynx

As for a modifier, there is not necessarily a commonly used modifier, many times there is not a modifier used for this coding scenario. Here is a link to our Tip of the Week on Modifiers where you can learn more about them and view a list of available modifiers:

http://www.dentalwriter.com/forum/default.aspx?g=posts&t=492

Hope this helps, have a great day