The ICD-10 code for a mass in the abdomen can vary depending on the specific location, nature, and suspected cause of the mass. Common codes may include R19.0 (Abdominal swelling, mass and lump), but it is essential to consult the ICD-10 manual or a medical professional to determine the most appropriate and accurate code based on a comprehensive medical evaluation. Improper coding can lead to billing errors and inaccurate medical records.