The fiscal year (FY) 2027 ICD-10-CM update includes 190 new diagnosis codes, 30 deleted codes, and four revised code descriptions. The new code set takes effect October 1, 2026, and applies to healthcare services provided through September 30, 2027.
For medical practices, staying current on these changes is important for maintaining accurate clinical documentation and coding. Using outdated or deleted codes—or documentation that doesn't support the specificity of a new code—can lead to claim corrections, additional administrative work, and potentially avoidable denials.
While coding teams should review the complete FY 2027 ICD-10-CM update and official coding guidelines, here are some of the important changes to know.
| Change | FY 2027 |
| New diagnosis codes | 190 |
| Deleted codes | 30 |
| Revised code descriptions | 4 |
| Effective date | October 1, 2026 |
| Key areas with changes | Obstetrics, cardiovascular conditions, toxic exposures and more |
The FY 2027 update introduces new diagnosis codes while deleting or revising others. A common theme across several categories is greater clinical specificity, allowing providers and coding teams to more precisely document and code certain conditions.
Notable areas affected by the FY 2027 changes include:
Here are a few of the changes medical practices and coding teams should have on their radar.
Obstetrics is one of the areas receiving significant updates for FY 2027.
The new code set adds greater specificity for ectopic pregnancies, including new codes that distinguish the location of an ectopic pregnancy and whether an intrauterine pregnancy is also present.
Examples include:
The FY 2027 update also adds new codes related to cervical and cornual ectopic pregnancies, further increasing the specificity available when coding these conditions.
For OB/GYN practices, these changes reinforce the importance of documentation that clearly identifies the type and location of an ectopic pregnancy when known.
FY 2027 also introduces a new ICD-10-CM category for continuing pregnancies following vanishing twin syndrome.
The new O31.4- category covers:
Continuing pregnancy after vanishing twin syndrome of one fetus or more
Codes within the category provide additional specificity based on factors such as trimester and fetus.
Providers and coding teams caring for patients with multiple gestations should familiarize themselves with the new category and the documentation needed to support the appropriate code.
Cardiovascular coding is another area where the FY 2027 update adds greater specificity.
For example, the existing code for dilated cardiomyopathy is being expanded to distinguish between different forms of the condition.
Deleted:
Added:
There are also changes to the coding of specified cardiac arrhythmias.
Deleted:
Added:
For cardiology practices and other organizations treating patients with these conditions, the changes provide more precise options for documenting and coding a patient's diagnosis.
The FY 2027 update also adds codes for toxic effects associated with certain chemical exposures, including cycloparaffins and other organic solvents.
Examples include:
These codes require the appropriate additional character to identify the encounter, such as an initial encounter, subsequent encounter, or sequela. Coding teams should consult the FY 2027 ICD-10-CM Tabular List and official coding guidelines when assigning these codes.
ICD-10-CM updates aren't simply a coding exercise. Diagnosis codes are part of the information practices submit on claims, making accurate coding an important component of an effective revenue cycle.
Issues can arise when:
Identifying these issues before the October 1 effective date can help practices reduce unnecessary claim corrections and coding-related rework.
Practices don't have to wait until October to prepare. Here are four steps billing leaders, practice administrators, providers, and coding teams can take now.
Review the changes most relevant to your specialties and patient population.
Providers should understand where greater specificity may require more detailed clinical documentation, while coding teams should know which commonly used codes are being added, revised, or deleted.
Identify the ICD-10-CM codes your practice uses most frequently and determine whether any are changing for FY 2027.
For specialty practices in particular, reviewing frequently used codes can provide a more focused approach than trying to address every change with the same level of attention.
Look at your existing denial trends and identify whether invalid, outdated, or insufficiently specific diagnosis codes are contributing to claim issues.
Understanding where coding-related problems already exist can help identify areas where additional provider education, documentation, or coding review may be valuable.
Confirm that your EHR, practice management system, clearinghouse, and other billing technology will support the FY 2027 code set beginning October 1.
Practices should also review internal coding resources, templates, documentation workflows, and training materials that may reference codes being changed or deleted.
The FY 2027 ICD-10-CM codes take effect October 1, 2026. They apply to healthcare services provided from October 1, 2026, through September 30, 2027.
The FY 2027 ICD-10-CM update includes 190 new diagnosis codes. It also includes 30 deleted codes and four revised code descriptions.
The National Center for Health Statistics (NCHS), part of the Centers for Disease Control and Prevention (CDC), is responsible for ICD-10-CM in the United States.
Healthcare organizations and coding professionals can access the official FY 2027 ICD-10-CM code files and supporting resources through the CDC's National Center for Health Statistics and the Centers for Medicare & Medicaid Services (CMS).
They can contribute to claim issues. Continuing to submit an invalid or deleted code, selecting an incorrect diagnosis code, or lacking documentation to support the appropriate level of specificity can result in additional claim work and, depending on payer requirements and the circumstances of the claim, denials.
The FY 2027 ICD-10-CM changes take effect October 1, 2026, giving practices an opportunity to prepare before the new code set becomes part of their day-to-day billing workflows.
Start by identifying the changes most relevant to your specialty, educating providers and coding teams, reviewing coding-related denial trends, and confirming that your technology and workflows are ready for the new codes.
Most importantly, practices and coding professionals should consult the official FY 2027 ICD-10-CM code set and coding guidelines from the CDC and CMS when making coding decisions.