Question: Since ICD-10 premiered, I’ve been having some trouble choosing the correct diagnosis codes for carpal tunnel syndrome (CTS). Can you offer any advice on choosing CTS codes using the new diagnosis system? North Carolina Subscriber Answer: You are not alone. Since ICD-10 premiered in October 2015, some coders have had trouble coding for conditions like CTS, which barreled into ICD-10 with a barrage of new, more specific codes. Master this code set, however, and put any CTS worries you have on ice. In ICD-10, the following CTS codes are available to the coder: Under the G56 category, you’ll find an Excludes1 note that prevents you from reporting CTS with “current traumatic nerve disorder — see nerve injury by body region.” Check notes for symptoms: Patients might initially present with complaints that are symptomatic of CTS. ICD-10 has made these codes more specific as well. Check out this rundown of some of the most common CTS symptoms, and their corresponding ICD-10 codes: Drill down with M79.6-: This diagnosis code now features a range of options based on anatomic site. The extended codes provide you with 30 options, including right, left and unspecified sites of arm (M79.601-603); forearm (M79.631-632, 639); upper arm (M79.621-622, 629); hand (M79.641-43); fingers (M79.644-646); thigh (M79.651-52,659); leg (M79.604- 605); lower leg (M79.661-662,669); feet (M79.671-673); and toe (M79.674-76). You’ll report M79.609 for pain in an unspecified limb. In your scenario, the M79.6- lower-extremity codes would almost certainly not be applicable for symptoms of CTS. The primary symptoms for CTS are numbness, tingling, and weakness.