ICD-10-CM Code Updates - April 1, 2025

CMS and the CDC have released the updates to the ICD-10-CM classification, as well as an update to the grouper (V42.1), that become effective on April 1, 2025. This Coding Tip covers the updates to the classification including additions, deletions and changes made in the Alphabetic Index, Tabular List and Official Guidelines for Coding and Reporting.

Where can I find the updates?

To download the updated files, use this link to the CDC website https://ftp.cdc.gov/pub/Health_Statistics/NCHS/Publications/ICD10CM/2025-Update/. The files include an updated version of the guidelines, the index and the tabular as well as an addendum with files that include only the specific changes being made to the classification. Reviewing the addendum makes it easy to see exactly what is being changed/updated.

ICD-10-CM Updates

There are no new diagnosis codes being implemented in the April 1, 2025, release of ICD-10-CM updates, but there are additions, deletions, and revisions to some index entries, tabular entries and instructional notes that have implications for the coding process and reimbursement.

In addition to the updates to the Index to Diseases and Injuries and the Tabular List, there were updates made to the Official Guidelines for Coding and Reporting.

Shown here is a summarization of the updates by section of ICD-10-CM.

Index to Diseases and Injuries

The are 4 alphabetic sections of the ICD-10-CM Index to Diseases and Injuries that have updates for April 1, 2025.

D

• The code directed for use by a search of the index under the terms Decrease(d) and blood, glucose, was changed from R73.09 Other abnormal glucose to E16.2 Hypoglycemia, unspecified.
• The three codes introduced in the October 2024 code updates to report hypoglycemia level (E16.A1, E16.A2 and E16.A3) have been moved to a further level of indentation under the terms. Decrease(d) and blood, glucose.
  • Decrease(d)
    • blood
      • glucose
        • level 1 E16.A1
        • level 2 E16.A2
        • level 3 E16.A3
  • The code directed for use by a search of the index under the terms Dissection, and precerebral artery, congenital (nonruptured), and Heartland A93.8 has been deleted.

I

• The code directed for use by a search of the index under the terms Infection, infected, infective (opportunistic) and bacterial, as the cause of diseases classified elsewhere, and Cronobacter (sakazakii) was changed from B96.89 Other specified bacterial agents as the cause of diseases classified elsewhere to A49.8 Other bacterial infections of unspecified site.

M

• The code directed for use by a search of the index under the terms Myocarditis (with atherosclerosis) (chronic) (fibroid) (interstitial) (odd) (progressive) (senile) and virus, viral was changed from I40.0. Infective myocarditis to B33.22 Viral myocarditis. 

Note: This is a significant update as code I40.0 is an MCC. The change to B33.22 for reporting viral myocarditis rather than I40.0 will result in the loss of an MCC.

P

• The spelling of jirovecii was corrected by adding a second letter “i” at the end of this term throughout the index, such as in the main term Pneumocystis jirovecii.

Tabular List of Diseases and Injuries

The are 8 chapters in the ICD-10-CM Tabular List that have updates for April 1, 2025.

Chapter 1 Certain infectious and parasitic diseases (A00-B99)

• A Use Additional code, if applicable, for associated cachexia (E88.A) instructional note was added under the section of codes for Tuberculosis (A15-A19).
• A spelling correction was made to the term “jirovecii” under category B59 Pneumocystosis.

Chapter 4 Endocrine, nutritional and metabolic diseases (E00-E89)

• A Use Additional code, if applicable, for associated cachexia (E88.A) instructional note was added under code E23.0 Hyperpituitarism.

Chapter 10 Diseases of the respiratory system (J00-J99)

• A spelling correction was made to the term “jirovecii” in the Excludes1 note under category J17 Pneumonia in diseases classified elsewhere.
• A Use Additional code, if applicable, for associated cachexia (E88.A) instructional note was added under category J65 Pneumoconiosis associated with tuberculosis.

Chapter 11 Diseases of the digestive system (K00-K95)

• The Excludes1 note that excluded code K59.0- Constipation from being reported with code K56.41 Fecal impaction has been deleted.
• A Use Additional code, if applicable, for ascites (R18.8) instructional note was added under codes K72 Hepatic failure, not elsewhere classified and K73 Chronic hepatitis, not elsewhere classified.
• An Excludes1 note for code K91.2 postsurgical malabsorption, not elsewhere classified was added under code K90.82 Short bowel syndrome.
• A Use Additional code, if applicable, for colostomy status (Z93.3) instructional note was added under codes K90.822 Short bowel syndrome without colon in continuity.

Chapter 14 Diseases of the genitourinary system (N00-N99)

• A Use Additional code, if applicable, to identify associated cachexia (E88.A) instructional note was added under category N18 Chronic kidney disease (CKD).

Chapter 15 Pregnancy, childbirth and the puerperium (O00-O9A)

• The word “uncomplicated” was added as a clarification at the end of the code title, “encounter for elective termination of pregnancy” found in the Excludes2 note found under category O04 Complications following (induced) termination of pregnancy.”
• A Use Additional code for hepatic obstruction (K76.89) instructional note was added under code O26.64 Intrahepatic cholestasis of pregnancy.

Chapter 19 Injury, poisoning and certain other consequences of external causes (S00-T88)

• The Excludes1 note that excluded the code categories for birth trauma (P10-P15) and obstetric trauma (070-071) from being reported with codes from Chapter 19 was changed to an Excludes2 note.

In the cases where an Excludes1 note was changed to an Excludes2 note, if the patient has both the condition listed in the code with the note and the excluded code, it is now appropriate to report codes for both conditions if they are not integral to one another and meet the criteria for reporting.

• The phrase “except as noted below” was added to the end of the coding instruction stating, “The appropriate 7th character is to be added to each code from category S06.” This instruction was given at the beginning of category S06 Intracranial injury, to draw attention to the exceptions outlined in the Note that accompanies these instructions which says, “7th characters D and S do not apply to codes in category S06 with 6th character 7 - death due to brain injury prior to regaining consciousness, or 8 - death due to other cause prior to regaining consciousness.”

Chapter 21 Factors influencing health status and contact with health services (Z00-Z99)

• Code block O94-O9A Other obstetric conditions, not elsewhere classified has been added to the list of codes included in the “Code first obstetric condition or encounter for delivery” instructional note under category Z3A Weeks of gestation.

Official Guidelines for Coding and Reporting

There is one ICD-10-CM coding guideline that has updates and one new guideline being added for April 1, 2025.

Chapter 1 Guidelines - COVID

In the guidelines for Chapter 1 Certain Infectious and Parasitic Diseases, there has been a considerable change to the direction provided in guideline I.C.1.g.1.h Asymptomatic individuals who test positive for COVID-19.

The previous iteration of the guideline directs the coder to follow guideline I.C.1.g.1.a and assign a code for COVID-19 infection based solely on documentation of a positive COVID-19 test result because a patient is considered to have a COVID-19 infection when they test positive.

Guideline content prior to April 1, 2025

I.C.1.g.1.h Asymptomatic individuals who test positive for COVID-19
For asymptomatic individuals who test positive for COVID-19, see guideline I.C.1.g.1.a. Although the individual is asymptomatic, the individual has tested positive and is considered to have the COVID-19 infection.

The updated guideline directs the coder to query the provider for confirmation of a COVID-19 diagnosis for asymptomatic patients who test positive for COVID-19 but for whom there is not a documented diagnosis of COVID. The guideline implies this practice is used to prevent coding false positive tests as active cases of infection. This guideline puts confirmation of the diagnosis back into the hands of the provider.

Guideline content on April 1, 2025

I.C.1.g.1.h Asymptomatic individuals who test positive for COVID-19
For asymptomatic individuals who test positive for COVID-19 and there is no provider documentation of a diagnosis of COVID-19, query the provider as to whether or not the individual has COVID-19. A false positive laboratory test is possible, and it is the provider’s responsibility to confirm the diagnosis and document accordingly.

Chapter 4 Guidelines - Obesity

A new section of chapter specific guidelines, I.C.4.b. Obesity, has been added for Chapter 4: Endocrine, Nutritional, and Metabolic Diseases (E00-E89). New codes for Obesity due to disruption of MC4R pathway (E88.82) and Obesity class (E66.8-) were released with the October 1, 2024, implementation of the FY 2025 ICD-10-CM code classification. This new section of the guidelines provides clarification around the assignment of these codes.

The general guideline (I.C.4.b) clarifies that codes for obesity can come from categories outside of category E66 Overweight and obesity. Specifically, codes E88.82 Obesity due to disruption of MC4R pathway and O99.21 Obesity complicating pregnancy, childbirth, and the puerperium.

Guideline I.C.4.b.1 relates directly to the assignment of codes from subcategory E66.81 Obesity class. The direction in this guideline outlines four important coding principles to follow when coding from this subcategory.

1. A 5th character indicating severity of the obesity is required for these codes. The severity options are class 1, class 2 and class 3.
2. Assignment of codes from subcategory E66.81 requires provider documentation of the obesity class in the medical record.
3. Codes from subcategory E66.81 may be reported with other obesity codes to fully describe the patient’s condition
4. If both morbid obesity and class 3 obesity are documented, only the code for class 3 obesity is assigned as it is more specific.

New ICD-10-CM Coding Guidelines, Effective April I, 2025

I.C.4.b. Obesity

The obesity codes in category E66, Overweight and obesity, include codes related to the cause of obesity, such as drug-induced obesity (E66.1), and codes related to effects of obesity, such as code E66.2, Morbid (severe) obesity with alveolar hypoventilation. There are other codes related to obesity in other categories of the classification, such as E88.82, Obesity due to disruption of MC4R pathway; and codes in fifth character subcategory O99.21, Obesity complicating pregnancy, childbirth, and the puerperium.

1) Obesity class
The obesity class codes in subcategory E66.81, Obesity class, require a fifth character to convey the severity of obesity. The obesity class should be documented in the medical record by the provider for these codes to be assigned. The obesity class codes can be reported with other obesity codes in the classification found in Chapters 4 and 15 to fully describe the condition. However, if both class 3 obesity and morbid obesity are documented, only a code for class 3 obesity should be assigned as it is more specific.

We recommend all coders download the complete set of addenda files from the CDC.gov website listed below to have a complete copy of the changes/updates going into effect on April 1, 2025, to use as a reference when coding.

References

• https://ftp.cdc.gov/pub/Health_Statistics/NCHS/Publications/ICD10CM/2025-Update/

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The information contained in this coding advice is valid at the time of posting. Viewers are encouraged to research subsequent official guidance in the areas associated with the topic as they can change rapidly.