Abnormal results of liver function studies. 1  R94.5 is a billable ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes. 2  Reimbursement claims with a date of service on or after October 1, 2015 require the use of ICD-10-CM codes. 3  This is the American ICD-10-CM version of R94.5.