Good news for medical coders—there are no new, deleted, or revised diagnosis codes in the April 2026 update to the ICD-10-CM for fiscal year 2026.

But before you relax… there’s a catch.

While the codes themselves remain unchanged, the Centers for Medicare & Medicaid Services has introduced important instructional note changes that can directly impact how you assign diagnosis codes starting April 1, 2026.

And yes—these changes can affect claim accuracy, denials, and compliance if overlooked.

No Code Changes… But Don’t Get Complacent

At first glance, this update seems simple:

✔ No new codes
✔ No deletions
✔ No revisions

However, the real impact lies in instructional note updates within the Tabular List, which guide how codes can or cannot be used together.

👉 For experienced coders, this means one thing:
Coding rules have changed—even if the codes haven’t.

The Big Shift: Excludes1 → Excludes2

One of the most important changes in this update is the conversion of several Excludes1 notes to Excludes2 notes.

Let’s break this down in a simple way.

What is an Excludes1 Note?

• Means “NOT coded here”

• You cannot report both codes together

• The conditions are considered mutually exclusive

What is an Excludes2 Note?

• Means “NOT included here”

• You CAN report both codes together

• Conditions may co-exist, if documented

Why This Matters

This change gives coders more flexibility.

👉 Conditions that were previously restricted from being coded together can now be reported if both are documented by the provider.

This directly impacts:

• Medical necessity

• Risk adjustment coding

• Reimbursement accuracy

Example: Chapter 2 Changes

In Chapter 2 (Neoplasms):

• Codes D18 (Hemangioma and lymphangioma)

• Codes D49 (Neoplasms of unspecified behavior)

👉 Their notes changed from Excludes1 → Excludes2

Coding Impact

Previously:
❌ You could NOT code both conditions together

Now:
✅ You CAN code both—if documentation supports it

ICD-10-CM April 2026 Changes at a Glance

Here’s a list of the ICD-10-CM chapters and codes with instructional note revisions:

MUST BUY CPT & ICD-10 CM  CODING EBOOKS 

Other Important Note Changes Coders Should Watch

Besides Excludes notes, there are additional updates you must understand:

1. “Code First” → “Code Also”

• Indicates sequencing flexibility

• Coders must rely more on clinical documentation

2. “Code Also” Added

• Encourages reporting additional related conditions

3. Deletion of Excludes1 Notes

• Removes previous coding restrictions

4. Inclusion Note Revisions

• Clarifies what diagnoses are covered under a code

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Real-World Coding Impact

These changes may seem minor—but they can have major real-world effects:

✔ More Accurate Coding

You can now report co-existing conditions more appropriately

✔ Reduced Claim Denials

Correct use of updated notes prevents coding conflicts

✔ Better Risk Adjustment

Capturing all relevant diagnoses improves patient risk profiles

✔ Improved Compliance

Following updated guidelines reduces audit risk

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What Medical Coders Should Do Now

To stay compliant and accurate, coders should:

✔ Review updated instructional notes in the Tabular List
✔ Educate providers about documentation requirements
✔ Update internal coding guidelines
✔ Audit frequently used codes affected by note changes
✔ Ensure coding software reflects April 2026 updates

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Final Thoughts

The April 2026 update to ICD-10-CM may not introduce new codes, but it significantly changes how coders apply existing ones.

👉 The shift from Excludes1 to Excludes2 is the biggest takeaway—giving coders more flexibility but also more responsibility.

Staying updated with these changes ensures:

✅ Accurate coding
✅ Proper reimbursement
✅ Reduced denials
✅ Strong compliance

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💡 Pro Tip for Coders:
Always remember—coding is not just about selecting codes, but applying the guidelines correctly. Instructional notes are just as important as the codes themselves.