Pathology/Lab Coding Alert

Question: We have had claim denials for certain lab tests ordered to monitor patient response to medication. What could be the reason for the denials, and how can we avoid them?

For example, a patient on Lipitor, a cholesterol- lowering drug, was denied for a liver function test (84450, transferase; aspartate amino [AST] [SGOT]) billed with the lipid panel 80061 (includes cholesterol, serum, total; lipoprotein, direct measurement, high density cholesterol; and triglycerides). Similarly, claims for a patient suffering from cardiac arrhythmia who takes Coumadin to thin his blood were denied for repeat tests of prothrombin time (85610), a finger-stick test for determining how fast the blood is clotting.

Virginia Subscriber

Answer: One common reason that tests to monitor the effects of medications are denied is the lack of appropriate diagnosis codes. In addition to listing the underlying medical condition, the claim should demonstrate that the tests in question deal with medication monitoring.

In your first example, the claim for the patient receiving Lipitor should show a diagnosis code for the underlying condition as 272.2 (disorders of carbohydrate transport and metabolism; mixed hyperlipidemia). But the claim should also list V58.69 (long-term [current] drug use; of other medications: high-risk medications). Because Lipitor can harm the liver, using the V code and listing the medication may indicate the medical necessity of the liver function test.

The second example should also list a V code related to medication. In this case, use V58.61 (long-term [current] drug use; of anticoagulants) to indicate Coumadin. This code indicates that the patients blood coagulation will need to be monitored on a regular basis. Many times, coders forget to use the V code, and this can result in claims denials. Because coverage rules vary, check with your local carrier or third-party payers to confirm that these codes indicate medical necessity for the tests being ordered. If they do not, have the patients sign an advanced beneficiary notification indicating that they will be responsible for the payment.

Answered by Laurie Castillo, MA, CPC, CPC-H, CCS-P, member of the National Advisory Board of the American Academy of Professional Coders.