Hint: Wait for the path report to avoid payer scrutiny. If you always use diagnosis code 238.2 (Neoplasm of uncertain behavior of skin) when you're reporting 11100 (Biopsy of skin, subcutaneous tissue and/or mucous membrane [including simple closure], unless otherwise listed; single lesion) for a biopsy procedure your physician performs, you're setting your practice up for disaster. The key to knowing when to use the "uncertain behavior" diagnosis code is understanding what that code descriptor really means. Follow these expert tips to ensure you're choosing the correct diagnosis code for all your 11100 claims. Wait For Pathology Before Choosing a Code When your physician performs a biopsy you should always wait until the pathology report comes back to choose the proper diagnosis and procedure codes to report -- even though this will not always affect the CPT code you will wind up choosing. Reason: Get to Know the Meaning Behind 'Uncertain' Codes When you report 238.2 as the diagnosis for a biopsy procedure, you're telling the payer that the pathologist said in his path report that he was uncertain as to the morphology of the lesion, says Barbara J. Cobuzzi, MBA, CPC, CENTC, CPC-H, CPC-P, CPC-I, CHCC, president of CRN Healthcare Solutions, a coding and reimbursement consulting firm in Tinton Falls, N.J., and senior coder and auditor for The Coding Network. "Uncertain behavior doesn't mean that the coder is uncertain or that the physician thinks the lesion looks suspicious but it might be benign," Bucknam explains. "Uncertain behavior means that a specimen has been examined by a pathologists and that the cells are of mixed types." How it works: "If you are not sure what a lesion is, you use unspecified, not uncertain," Cobuzzi explains. "Uncertain is reserved for a pathologist only diagnosis." Example: Caution: Don't Rush Coding Just to Get Paid You should never code just to ensure you'll be paid for a procedure. In the case of a biopsy, waiting to code until you have the pathology report should not affect your reimbursement amount anyway. You may have to wait a bit longer to see the reimbursement if you need to hold a claim while you wait for the pathology report, but your coding will be much more accurate. "If you biopsy a lesion and the results come back as precancerous this is exactly the diagnosis you would use so it is a perfectly payable diagnosis," Bucknam says. "On the other hand, insurers are looking for more and more reasons to deny payment. If you had performed a biopsy and indicated that the patient has hyperplasia and then the doctor found out that the biopsy indicated melanoma and the patient returned to have excision of the melanoma and the insurer ever compared the documentation there could be problems." Additionally: "A payer could actually bring a practice up on charges (civil or criminal) for improperly coding the ICD-9 since that is what determines the 'medical necessity' for payment from the payer," Cobuzzi adds. Bottom line: