Ohio Subscriber
Answer: You should bill both codes. Because anxiety is the initial complaint and the reason the physician ordered the blood test, report 300.00 (anxiety state, unspecified) as the primary diagnosis code. The test is ordered to make sure the patients medication is not affecting his or her blood level, so use V58.69 (long-term [current] use of other medications) as the secondary code.
The anxiety diagnosis supports the reason for the office visit, while the V code supports the medical necessity for the lab work. Also report the V code for the cause of the anxiety from the V60 series for example, V62.89 (other psychological or physical stress, not elsewhere classified, other). All three diagnosis codes would be used with the appropriate E/M visit code.
On the claim form, list 300.00 first, the appropriate code from the V60 series second, and V58.69 last. The anxiety diagnosis code is not paid by all carriers, but most will reimburse for the V60 series code. If the carrier denies both, it will pay for the test, but not for the office visit.