The implementation of ICD-10-CM brought many changes to the world of coding. Most notable was the increase in available diagnosis codes from 14,000 to 68,000 when ICD-10-CM was first implemented in October 2015. With the additions for FY 2017 now pushing 70,000, it is crucial to follow the conventions, symbols, and guidelines provided throughout the book.
The conventions are instructional notes incorporated within the ICD-10-CM codebook. It is important to understand these conventions because they explain the format and structure of both the index and the tabular list. These include abbreviations such as NEC (not elsewhere classified) and NOS (not otherwise specified), brackets enclosing synonyms or manifestation codes, parentheses enclosing supplemental words, and colons to signify an incomplete term. “NOTES”, which is located immediately under a code title, is a convention clarifying the content of the category and often providing examples. There are also instructions for ‘includes’, ‘excludes’, ‘code also’, and ‘code first’ which help guide you through the coding process.
There are also specific symbols and color-coding located in the tabular list. The symbol seen most often is the ‘additional character required indicator’ placed in front of codes. This will be a 4, 5, 6, or 7 in a red circle next to the code prompting the coder to read further for a more specific code choice. There can also be a 7 within a blue circle to indicate the final code should include a seventh character following one or more “X” placeholders. Some symbols appear to the right of the code columns and these may include age and/or sex conflict warnings. An example would be an “A” in red next to the codes for age related cataract of the eye. That “A” clarifies that the code may only be applied to a patient in the age range of 18 to 124. A sex conflict symbol appears next to conditions that can only exist in male or female patients such as cervical or prostate cancer. There are other symbols defined in the front of the ICD-10-CM codebook that should be referenced for correct coding practices.
The guidelines are extensive instructions provided by the Centers for Medicare and Medicaid Services (CMS) and the National Center for Health Statistics (NCHS) and approved by the American Hospital Association (AHA) and the American Health Information Management Association (AHIMA). These four organizations make up the Cooperating Parties for the ICD-10-CM. The coding rules defined in the guidelines were developed to accompany and compliment the conventions. Each chapter of the ICD-10-CM has its own specific guidelines that clarify the conventions used in that chapter in addition to code sequencing instructions and other important information for that section of codes.
These are just some highlights of the instructional information provided for you. Please refer to your codebook for the complete information. Having a clear understanding of the conventions, symbols and guidelines will help ensure the accurate selection of diagnosis codes.