Question: We have a question concerning pulmonary embolism and deep vein thrombosis (DVT) codes and their use in M0230/M0240. We have been using V12.51 (History of venous thrombosis and embolism) for home care diagnoses in all cases for pulmonary embolisms and also for DVT unless there is ongoing treatment for the DVT. Is this correct? Oklahoma Subscriber Answer: Sometimes the patient is receiving treatment for an existing embolism or DVT even after discharge from a hospital; sometimes the treatment is prophylactic -- the original problem was resolved, but the patient is at risk for further development. Before you code, review any referral documentation carefully for helpful information, such as "history of," and ask the patient and caregiver about the approximate time frame that the DVT or PE was diagnosed and first treated. If in doubt, call the physician for details.