Cozy up to G-codes and modifiers for tracking patient status, goals and severity level. Listed below are two tables to guide you through CMS' functional status reporting in 2013. The first lists functional limitation G-codes and the second lists the severity level modifiers. You must report these on outpatient therapy claim forms at admission, every 10 treatment days, and at discharge starting Jan 1, 2013. If you do not report patient status by July 1, 2013, CMS may begin denying payment.