With so many organizations touting large numbers of ICD-10-CM updates, it can be difficult to gauge how the 2026 diagnosis coding changes will impact your daily work. In this post, I’ll highlight the most notable revisions and provide a link at the bottom of the page to help you explore all revisions, additions and deletions.
In Section I.C.1 of the official guidelines, you’ll find several new instructions regarding reporting of HIV. BCA recommends a thorough review of these instructions prior to commencing coding activities on October 1, 2025.
New code E11.A (Type 2 diabetes mellitus without complications, in remission) now allows providers to report the successful treatment of Type 2 diabetes into a remissive status. This is only reported when a patient did not develop complications of diabetes while fighting the disease. Instructions in the guidelines also clarify that the term “resolved” is not synonymous with remission.
G35 Multiple sclerosis now requires additional characters to specify the type of MS, such as:
G35.A Relapsing-remitting multiple sclerosis
and
G35.B1 Active primary progressive multiple sclerosis
An unspecified option (G35.D) should be utilized only when further specificity is unknown.
Chapter 7 adds a subcategory at H05.83 for Thyroid orbitopathy with options for laterality.
Additionally, other specified inflammation of the eyelid expands options for specific eyelid(s) involved.
Chapter 9 has minimal code changes, but a significant and notable shift in guidelines. Section I.C.9.a.1 states:
“Hypertension with heart conditions classified to I50.- Heart failure, I51.4 Myocarditis, unspecified, I51.89 Other ill-defined heart diseases, and I51.9 Heart disease, unspecified, is assigned to a code from category I11, Hypertensive heart disease. Use additional code(s) from category I50, Heart failure, or I51, Complications and ill-defined descriptions of heart disease, to identify the heart condition.”
“Hypertension with heart conditions classified to I51.5, Myocardial degeneration, or I51.7, Cardiomegaly, is assigned to a code from category I11, Hypertensive heart disease. No additional code is assigned to identify the specific heart condition.”
The guidelines go on to state that these conditions are coded separately if the provider has documented they are unrelated to hypertension. Watch the AHA Coding Clinics for further guidance on this significant change.
For skin disorders, the flank now has separate codes for cutaneous abscesses, furuncles, cellulitis and lymphangitis. Non-pressure chronic ulcers saw significant expansion to specify site and depth or severity.
In Chapter 18, Pelvic and perineal pain is now specified by laterality. The flank once again receives attention, with updates for pain and tenderness to include laterality. Cannabis hyperemesis syndrome is introduced at R11.16, with instructions to code also cannabis use, abuse or dependence as well as associated manifestations such as dehydration or electrolyte imbalance. Subcategory R39.85 offers opportunity to capture costovertebral (angle) tenderness by laterality.
Chapter 19 (injuries) saw further expansion related to the flank, including but not limited to contusions, lacerations, puncture wounds and insect bites.
Poisoning, adverse effects, and underdosing of fluoroquinolone antibiotics now have their own subcategory. Reactions (including anaphylaxis and adverse reactions) to eggs, milk, and other dairy products have been added, with new specificity for whether the patient tolerates the same product when baked.
Finally, further specificity is found in a handful of Social Determinants of Health categories. This includes housing instability, financial insecurity, and material hardship.
Revised instructions (Excludes 1 and 2, Code Also, etc.) are littered throughout the Tabular List. This serves as a friendly reminder to always pair entries found in the Alphabetic Index with a thorough review of Tabular List instructions. Even if you’re sure you know what the Tabular List instructs, October 1st may bring guideline changes that are worthy of your careful review.
CMS.gov shares very helpful information for us to reference at the following link:
https://www.cms.gov/medicare/coding-billing/icd-10-codes
If you’d like to carefully review all additions, deletions and revisions, I recommend opening the 2026 Addendum file. This is an excellent tool to share with anyone who may need to review changes prior to EMR updates.
Need help navigating ICD-10-CM changes? Contact us at info@bcarev.com to start the conversation.