Cross walk ICD9-10 is an app designed for medical professionals and medical coders. This extremely easy to use, one time install app helps you convert ICD9 codes to ICD10 codes using a crosswalk. Accurate diagnosis codes are essential for medical billing. Only the most detailed claims will ensure maximum reimbursement in physician and inpatient coding. Dont be behind the curve when it comes to ICD10, the transition is mandatory.