New 2027 ICD-10 codes are out (effective Oct. 1)—what you need to know

By Brian Murphy

The 2027 ICD-10-CM (diagnosis) and ICD-10-PCS (procedure) codes are out. You can view them on the CMS website at the link below. They take effect Oct. 1, 2026.

So what do we have? At a high level:

• ICD-10-CM: 190 new codes, 30 deletions, 4 code revisions
• ICD-10-PCS: 101 new codes, 38 deletions, 3 code revisions

Note: The updated 2027 PCS guidelines are also out, but not the updated ICD-10-CM guidelines. Unfortunately I don’t have room to cover the PCS codes, but what follows is a summary of the diagnosis changes.

The most relevant/eye-catching change is two new codes adding BMI specificity in the lower range, replacing the familiar Z68, as follows:

• Delete: Z68, Body mass index [BMI] 19.9 or less, adult
• Add: Z6818, Body mass index [BMI] 18.4 or less, adult
• Add: Z6819, Body mass index [BMI] 18.5-19.9, adult

Beyond BMI, the broader diagnostic code updates reveal several themes: increased clinical specificity, recognition of emerging diseases and genetic syndromes, expanded maternal-fetal reporting, and enhanced tracking of environmental and occupational exposures.

This is a summary from my non-clinical perspective. A lot of new specificity added. Note that we don’t know if any of these new codes are CC/MCCs or hold other payment ramifications, so we must wait until the release of the 2027 IPPS final rule.

Cardiology is one of the most heavily affected areas. CMS has expanded coding options for cardiomyopathies and cardiac arrhythmias, adding distinctions for familial-genetic dilated cardiomyopathy (I4201), arrhythmogenic cardiomyopathy (I4281), Brugada syndrome (I4981), catecholaminergic polymorphic ventricular tachycardia (CPVT, I4722), ventricular bigeminy, and other rhythm disorders. For CDI/coding professionals, these additions are a continued shift toward capturing disease etiology and severity rather than relying on broad “other” or unspecified diagnoses.

In short, check out the I series section.

Another trend is the continued growth of precision medicine and genomics. New codes identify inherited cancer predisposition syndromes such as Lynch syndrome (QA171), BRCA-associated familial cancer syndromes, and Li-Fraumeni syndrome, and Loeys-Dietz syndrome and VEXAS syndrome (M043).

How common these conditions are and how often you might already encounter them in the documentation I cannot say.

Maternal-fetal medicine sees a significant expansion as well. New codes distinguish multiple types of ectopic pregnancy, including cesarean scar, cervical, cornual, and interstitial pregnancies, while an extensive new code set addresses pregnancies complicated by vanishing twin syndrome.

Several changes also focus on postprocedural and long-term complications. We’ve got new codes for post-bariatric hypoglycemia, nipple ischemia and necrosis following procedures, intestinal failure-associated liver disease (K7683), and more granular fibrosis staging.

From a public health perspective, the code set continues to expand its ability to track environmental and toxic exposures. New codes address exposure to burn pits, Agent Orange, blast overpressure, gadolinium, and a variety of toxic substances.

Reference

• CMS, ICD-10: https://www.cms.gov/medicare/coding-billing/icd-10-codes