Tips for Preparing for New Coding Changes for 2023

New codes become effective Oct. 1, 2022.

With the start of fiscal year (FY) 2023 right around the corner, this is a good time for clinical documentation integrity (CDI) professionals update their practices to reflect FY 2023 changes. I’m sure most of you have already downloaded FY 2023 ICD-10-CM/PCS and the Official Coding Guidelines, but there are some other lesser-known resources that can help you prepare for FY 2023. 

When you visit the 2023 ICD-10-CM on CMS.gov to get a copy of the FY 2023 ICD-10-CM Coding Guidelines, it is often worthwhile to download the 2023 Addendum. As I prepare for FY 2023, I like to review the ICD-10-CM Tabular List of Disease and Injuries 2023 Addenda.  The addenda reveal what changes occurred in the tabular list by each chapter so it is an easy way to find new, deleted and revised ICD-10-CM codes. There is a table that I’ll mention below that also lists new, deleted, and revised codes, but I like to see the changes in the context of the tabular list because then I gain insight into how to properly use the code. 

For example, did you know code E87.2 for acidosis has been expanded? Instead of one code for all types of acidosis, E87.2 has been expanded to four different codes and these include the following:

• Code E87.2 acidosis has been deleted
• E87.20 is a new code for acidosis, unspecified but still includes lactic acidosis NOS and metabolic acidosis NOS
• E87.21 is a new code for ACUTE metabolic acidosis that includes acute lactic acidosis
• E87.22 is a new code for CHRONIC metabolic acidosis that includes lactic acidosis with a code first note for the underlying etiology, if applicable
• E87.29 is a new code for other acidosis that includes respiratory acidosis NOS

What I find most interesting is the addition of acuity with the diagnosis of acidosis. Code E87.2, which included both acute and chronic acidosis was classified as a complication (CC), but I wonder if differentiating between acute and chronic acidosis will eventually result chronic metabolic acidosis being removed from the CC list. Hold onto that thought as I tell you a way to check out if these new codes are classified as a CC or not.

The other must have resource from the 2023 ICD-10-CM CMS.gov webpage is the 2023 code tables, tabular and index.  I like to keep a PDF copy of the alphabetic index and tabular list so I can quickly look up diagnoses by either description or ICD-10-CM code.  Again, some of you may find it faster to use a grouper, but with the type of work I do, I often what to know every term associated with a particular ICD-10-CM code.  Let me give you an example, there are many “other” and “unspecified” codes, and the tabular list does not include all synonyms, so I often search the alphabetic index by that particular ICD-10-CM code to find those other inclusive conditions. Let’s say I wanted to know what diagnoses are included in code G92.8 Other toxic encephalopathy. The tabular list only includes toxic encephalitis and toxic metabolic, but when you search the alphabetic index by “G92.8” you’ll find the additional diagnoses of “drug included metabolic encephalopathy,” “Jamaican neuropathy,” “Jamaican paraplegic tropical ataxic-spastic syndrome,” and “heroin vapor leukoencephalopathy” to name a few.  The tabular list is not all inclusive of every condition that will map to a particular ICD-10-CM code.

The next site I would strongly encourage you to visit is the FY 2023 IPPS Final Rule home page. There are a couple of different references that I like from this site. Primarily, I get my own copy of Table 5, the list of MS-DRGs, relative weighting factors, and geometric and arithmetic mean length of stay. If you didn’t know, the associated relative weights and length of stay are updated annually based on prior year claims.  Many organizations have analyst who will compare the current year Table 5 to the prior year Table 5 to identify potential revenue shifts as some MS-DRGs may have lower or higher relative weights compared to the prior year.  I like having an electronic copy of the MS-DRGs because I find it easier to search than using a book.

This site is also where you will find the tables that outline all ICD-10-CM and PCS code changes. Table 6A includes all the new diagnosis codes for FY 2023.  Table 6J includes ICD-10-CM diagnosis codes classified as CCs in FY 2023.  I often focus on tables 6J.1 and 6J.2 because these tables list what codes have been added or removed from the CC list.  Similar tables exist to identify these changes among diagnoses classified as MCCs. In a moment, I’ll share another tool where you can also check ICD-10-CM codes against the FY 2023 CC and MCC list. 

I often find that a more useful on-going resource, but I start with these lists so I can begin educating my peers and providers about the impeding code changes, so we aren’t caught off guard. For example, as expected E87.2 has been removed as CC, appearing on Table 6J.2 because the code no longer exists.  However, the new acidosis codes are all included on Table 6J.1 for additions to the CC list.

ICD-10-CM/PCS MS-DRG v40.0 Definitions Manual page

One of my favorite resources is the ICD-10-CM/PCS MS-DRG v40.0 Definitions Manual. This version will be in effect from 10/1/22 to 3/31/23.  Before you think the associated dates are a typo, remember updates now occur biannually. Why do I love this resource? It allows me to quickly research how ICD-10-CM/PCS codes impact MS-DRG assignment. Whether you are new to CDI or a veteran, this website has some great resources to help you understand MS-DRG methodology. For example, did you know MS-DRG v40.0 contains a combination of 73,639 diagnosis codes and 78, 494 procedure codes?  The design and development of the diagnosis related group (DRG) reference includes a table that outlines the breakdown of base MS-DRGs. 

The ICD-10-CM/PCS MS-DRG v40.0 Definitions Manual lists all the MS-DRGs by Major Diagnostic Category (MDC).  Within each MDC the associated MS-DRGs are separated by surgical and medical MS-DRGs.  Want to know what ICD-10-CM and/or ICD-10-PCS codes map to a particular MS-DRG?  This is the resource for you when you are doing research on the fly or don’t have access to a grouper. 

Perhaps the most valuable resource associated with the Definitions Manual is the appendixes. With the start of a new fiscal year, it is often hard to remember which diagnoses are classified as a CC or MCC.  Appendix G includes Diagnoses defined as complications or comorbidities, numerical list of ICD-10-CM codes that are classified as CCs. Appendix H includes those diagnoses defined as major complications or comorbidities or (MCC).

Remember those new acidosis codes I mentioned? Rather than having to access all the different tables within the FY 2023 Final Rules page, I find referencing Appendix G a lot easier. A quick search of Appendix G allows me to verify that all the new acidosis codes (E87.20-E87.29) are currently classified as CCs in FY 2023.

I hope you find these resources as helpful as I do as you prepare for FY 2023. 

EDITOR’S NOTE: For additional information on the new ICD-10 codes and other important information, download the on-demand 2023 IPPS Three-Day Coding Summit.