What is ICD-10-CM?
The ICD-10-CM is a catalog of diagnosis codes used by medical professionals for medical coding and reporting in health care settings. The Centers for Medicare and Medicaid Services (CMS) maintain the catalog in the U.S. releasing yearly updates. The 2023 ICD-10-CM is the latest code set revision and is valid for discharges and patient encounters occurring from October 1st, 2023 through September 30, 2024.
ICD-10-CM codes are composed of codes with 3, 4, 5, 6 or 7 characters. Codes with only three characters are usually the headings of a category of codes. A three-character diagnosis code should only be used only if it is not further subdivided in more specific codes. Diagnosis codes with five or six characters provide greater detail. ICD-10 codes should be used to the highest number of digits available or highest specificity.
Codes in chapters M, O, R, S, T, V, W, X, Y require the use of a seventh character code. If the code has fewer than six characters the placeholder "x" is used to make sure that the seventh character is always in the seventh position.
