FY 2026 ICD-10-CM Code Updates

The Center for Medicare and Medicaid Services has released the FY 2026 updates to the ICD-10-CM code classification. There are almost twice as many new codes this year as compared to last year, with the number of codes being added to a single chapter ranging from 1 to 213.

This this table show the breakdown of code updates by chapter of ICD-10-CM.

ICD-10-CM Coding Guidelines

The updates to the ICD-10-CM Official Guidelines for Coding and Reporting are extensive for 2026. The updates include the addition of new guidelines as well as rewording or additions to existing guidelines.

A significant percentage of updates to the guidelines are being made in Chapter 1 to the guidelines for coding for HIV disease.

For this chapter, one new guideline was added, and eight other guidelines have been edited. The additions and wording changes provide clarification and specification around current principles for coding HIV without really changing the coding principles outright.

For example, the title and wording of guideline I.C.2.e.2 was updated to specify that this guideline applies to admissions/encounters involving chemotherapy, immunotherapy and radiation therapy for treatment of a neoplasm/neoplastic disease.

A new guideline was added as the first guideline under the section titled Selection and Sequencing of HIV codes. Adding this guideline at the beginning of the section has pushed the subsequent nine guidelines down in the section causing the numbering of the guidelines to change. Some guidelines have been renamed even if the content of the guideline remained the same.

The new guideline, I.C.1.a.2.a, is titled HIV disease. This guideline clarifies that any documentation of a condition as AIDS, HIV Disease, HIV related illness or any description of a diagnosis resulting from the patient being HIV positive is to be reported with code B20 Human immunodeficiency virus Additional new and updated guidelines are listed below. Each guideline should be reviewed with an eye towards any changes it brings to correct coding practices.

ICD-10-CM Alphabetic Index

Most of the entries added to or deleted from the index are related to the addition of new codes or the addition of new inclusion terms being added under some codes. There are several instances though where the index has changed the code directed for use for a particular search of the index or added new search terms providing a way to locate a code but not due to the introduction of a new code.

Examples:

With the addition of codes for idiopathic, infantile calcification of arteries, the code directed for use by the index changes from a “Q” code (Q28.8) for a congenital condition from chapter 17 to an “E” code (E83.820) from chapter 4, so this condition has been reclassified to a whole different chapter of ICD-10-CM.

New terms have been added leading to code O36.59- to report fetal growth restriction.

Subterms have been added to allow for reporting dactylitis and priapism as complications of sickle-cell disease.

ICD-10-CM Tabular List

The greatest number of updates to ICD-10-CM for 2026 were made within the Tabular List. Updates consist primarily of adding new codes or expanding existing codes to provider greater specificity, but there were also a notable number of updates to instructional notes, such as the addition of Code first, Code Also and Use Additional Code notes, and Excludes 1 notes being changed to Excludes 2 notes. When coders begin assigning codes on October 1, 2025, it is recommended to pay particular attention to reviewing any relevant instructional notes in the Tabular List for applicable changes.

2026 ICD-10-CM Significant Updates by Chapter

The list below highlights some of the significant 2026 updates to ICD-10-CM by chapter.

• Chapter 4: Endocrine, Nutritional and Metabolic Diseases
  • Four new subcategories of codes have been added
    • E72.53- Primary hyperoxaluria
    • E72.54- Secondary hyperoxaluria
    • E78.01- Familial hypercholesterolemia
    • E88.1- Lipodistrophy, not elsewhere classified
  • Subcategory E83.8 was expanded with new codes for arterial calcification of infancy
  • 23 additional new codes have been added to this chapter
  • A new code was added to report type 2 diabetes mellitus without complications in remission. This code has a corresponding new guideline I.C.4.a.1.b that provides direction related to assignment of this code.

• Chapter 6: Disease of the Nervous System
  • The codes in category G35 Multiple Sclerosis have been expanded to allow for reporting of MS documented as
    • relapsing-remitting
    • active/non-active primary progressive
    • active/non-active secondary progressive.
  • New codes have been added to report:
    • Primary progressive apraxia of speech (G31.87)
    • Limb girdle muscular dystrophy due to fukutin related protein dysfunction (G71.036)

• Chapter 7: Diseases of the Eye and Adnexa
  • Codes in category H01.8 Other specified inflammations of eyelid have been expanded to specify which eyelid(s) are affected (right/left, upper/lower).
  • Codes in categories H05.831 Thyroid orbitopathy and H40.84 Neurovascular secondary angle closure glaucoma have been expanded to specify laterality.

• Chapter 12: Diseases of the Skin and Subcutaneous Tissue
  • Codes have been added to include “flank” as an anatomic site for the following conditions:
    • Cutaneous abscess
    • Furuncle Cellulitis
    • Acute lymphangitis
  • 40 new codes are being added to subcategory L98.4 Non-pressure chronic ulcer of skin for the following sites:
    • Abdomen
    • Chest
    • Neck
    • Face
    • Groin
  • A new subcategory with 72 new codes (L98.A) is being added to report Non-pressure chronic ulcer of upper limb. These codes are further divided by laterality and severity for these sites:
    • Upper arm
    • Forearm
    • Hand

• Chapter 17: Congenital Malformations, Deformations and Chromosomal Abnormalities
  • Subcategory Q87.8 Other specified congenital malformation syndromes, NEC is getting 2 new codes to report Hao-Fountain Syndrome and CTNNB1 Syndrome
  • Subcategory Q89.8 Other specified congenital malformation is getting 2 new codes to report Kabuki Syndrome and Other specified congenital malformations
  • 5 new codes are being added to report Usher Syndrome by type.
  • A new category QA0 Genetic Disorders, Not Elsewhere Classified is being added to Chapter 17. This category includes code to report:
    • Neurodevelopmental disorders related to pathogenic variants in certain specific genes (QA0.01-)
    • Other neurodevelopmental disorders related to pathogenic variants in other specific genes (QA0.8)

• Chapter 19: Injury, Poisoning and Certain Other Consequences of External Causes
  • In this chapter new codes are being added related to locations on the trunk, especially the flank, in relation to injuries:
    • Contusions of abdominal wall, groin and flank (S30.1-) (3 codes)
    • Superificial injuries to flank (S30.8-) (6 codes)
    • Open wound of abdominal wall without penetration into peritoneal cavity, right, left or unspecified flank (S31.1-) (18 codes)
    • Open wound of abdominal wall with penetration into peritoneal cavity, right, left or unspecified flank (S31.6-) (18 codes)
  • The designation of “wrist” is being removed from codes in subcategory S62.9 Fracture wrist and hand level.
  • A new subcategory T36.A- is being added to report poisoning, adverse effect of and underdosing of fluoroquinolone antibiotics.
  • A new subcategory T66.84- is being added to report toxic effect of xylazine.
  • Codes are being added for effects of Gulf War illness (T75.830) or Effects of other war theater (T75.838)
  • Subcategories T78.07 and T78.08 Anaphylactic reaction due to milk and dairy products or eggs respectively and T78.11 and T78.12 Other adverse food reaction due to milk and dairy products or eggs respectively are being expanded to specific whether the patient has a tolerance or reactivity to milk/egg that has been baked.

• Chapter 20: External Causes of Morbidity
  • New codes are being added for:
    • Other sharp object entering into or through a natural orifice (W44.H9)
    • Fishing hook entering through skin (W45.3)
  • Categories Y36 Operations of war and Y37 Military operations are getting codes to report low/high level blast over pressure.
  • Category Y93 Activity codes is getting new codes for splitting wood and other outdoor activity.

• Chapter 21: Factors Influencing Health Status and Contact with Health Services
  • New codes are being added to report
    • Genetic susceptibility to disease (Z15)
    • Encounters for prophylactic surgery (Z40.8-)
    • Problems related to employment and unemployment (Z56)
    • Problems related to housing and economic circumstances (Z59)
    • Other contact with and (suspected) exposures hazardous to health (Z77)
    • Family and personal history of malignant/in-situ neoplasm of fallopian tubes (Z80.44, Z85.4A, Z86.00A)
    • Family history disorder of kidney and ureter (Z84.1)
    • Exposure to diethylstilbestrol (DES) (Z84.A) and Personal risk factor of exposure to DES (Z91.B)
    • Allergy to milk products (Z91.011-)
    • Allergy to eggs (Z91.012-)

Prepare Now

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• FY 2026 ICD-10-CM Code Updates
• FY 2026 ICD-10-PCS Code Updates
• FY 2026 Inpatient Prospective Payment System (IPPS) Updates
• FY 2026 CPT and HOPPS Updates (Coming December 2025)

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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.