Every year, the Centers for Medicare & Medicaid Services (CMS) updates the ICD-10-CM coding system, the standard for classifying diagnoses and inpatient procedures. These revisions, effective October 1, 2024, reflect the latest advancements in healthcare. Staying current with these updates is crucial for healthcare professionals, providers, and payers to ensure accurate and efficient billing.
Objective
This article breaks down the key changes in the ICD-10-CM 2025 updates. Here's what we'll cover:
- Highlight the newly added diagnosis codes or revisions made for 2025.
- Pinpoint the medical specialties and areas where these new codes are updated.
- If any codes are being deleted in the 2025 update.
Summary
Chapter Wise Classification
Breaking down the chapter-wise code updates
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Chapter 2: Neoplasms
The new 63 diagnosis codes are added under Lymphoma category C81- C88, depending on whether the condition is “in remission” or “not having remission.”
Chapter 4: Endocrine, Nutritional, and Metabolic Diseases
The new 16 diagnosis codes are added, and two codes are deleted and expanded further.
Below are the categories in which new codes are added.
Chapter 5: Mental, Behavioral and Neurodevelopmental Disorders
The existing codes for anorexia and bulimia from the Eating Disorder Category (F50) are expanded based on the severity, such as
- Mild
- Moderate
- Severe
- Extreme
- In remission
- Unspecified
A total of 4 codes are deleted and expanded into 26 new codes based on specific severity.
Chapter 6: Diseases of the Nervous System
The chapter includes seven new codes for
- KCNQ2-related epilepsy
- Serotonin syndrome
- Developmental and epileptic encephalopathy
Chapter 9: Diseases of the Circulatory System
Four new codes were added, and 2 code descriptions were revised for the pulmonary embolism from the I26 category code. The new codes were added for Cement and Fat pulmonary embolism.
Chapter 10: Diseases of the Respiratory System
Seven new codes were added for Internal nasal valve collapse in the J34 category: Other and unspecified nose and nasal sinus disorders.
Chapter 11: Diseases of the Digestive System
New 27 codes were added under fissure and fistula of anal and rectal regions K60 for the below category based on the nature of the occurrences and the complexity/severity of the diagnosis.
Chapter 13: Diseases of the Musculoskeletal System and Connective Tissue
This section on intervertebral disc degeneration (category M15) now provides more detailed codes for the lumbar and lumbosacral regions. Pain specific location is added:
- Back pain only: For cases where the pain is limited to the back.
- Leg pain only: For cases where the pain radiates down the leg (like sciatica).
- Both back and leg pain: When both areas are affected.
- No specific pain location: When the documentation doesn't specify where the pain is.
Diagnosis code M659 Synovitis and tenosynovitis, unspecified, is expanded with 24 codes based on the location (Body part). The changes are elaborated in the table below.
Chapter 19: Injury, Poisoning, and Certain Other Consequences of External Causes
30 new codes are added under this section for the below diagnosis
- Poisoning and adverse effects by immune checkpoint inhibitors and immunostimulant drugs (T45.Axxx)
- Disruption of internal operation (surgical) wound, not elsewhere classified (T81.32) category code expanded into below codes.some text
- Gastrointestinal tract anastomosis, repair
- Closure of internal operation (surgical) wound of abdominal wall muscle or fascia
- Closure of other specified internal operation (surgical) wound
- Unspecified operation wound
Chapter 21: Factors Influencing Health Status and Contact with Health Services
A total of 25 new codes are added, and two codes are deleted. These codes are updated under
- Genetic susceptibility to disease (Z15) category for epilepsy and obesity
- Estrogen receptor status (Z17) category for the Progesterone receptor, Human epidermal growth factor, and Hormone receptor
- Encounter for other aftercare and medical care (Z51), aftercare for sepsis
- Housing and economic circumstances problems (Z59), category related to insurance
- Blood type (Z67) category for Duffy blood type
- Pediatric Body mass index [BMI] (Z68) category
- Personal history (Z86) category for colon polyps
ICD-10-CM Guidelines
Chapter 2: Neoplasms
- Coding for Breast Implant-Associated Anaplastic Large Cell Lymphoma (BIA-ALCL)
- When coding for BIA-ALCL, use the following specific codes instead of the general complication codes found in Chapter 19:some text
- C84.7A: This code is used for BIA-ALCL which is currently active.
- currently active for BIA-ALCLC84.7B: This code is used when BIA-ALCL is in remission.
- Coding for malignant neoplasm of lymphoid tissue metastasizes
If a lymphoma spreads beyond the lymph nodes to other organs, use a code from categories C81-C85 that specifically indicates "extranodal and solid organ sites".
Example: If a diffuse large B-cell lymphoma spreads to the lung, brain, and left adrenal gland, use code C83.398.
Chapter 4: Endocrine, Nutritional, and Metabolic Diseases
- For presymptomatic type I diabetes mellitus or early-stage type 1 diabetes that predates the onset of symptoms, assign code from category E10.A- Type 1 diabetes mellitus, presymptomatic.
Chapter 9: Diseases of the Circulatory System
- The guidelines for I21.A1 Type 2 myocardial infarction due to demand ischemia or secondary to ischemic imbalance are revised. The underlying etiology that causes the type 2 myocardial infarction, if applicable, should be coded first. Previously, its mandate was to assign myocardial infarction etiology first.
In conclusion, accurate coding is the foundation for efficient healthcare operations and Payment Integrity. By embracing the ICD-10-CM 2025 updates, you can optimize reimbursement, minimize claim denials, and ultimately enhance patient care.
Reference
- https://www.cms.gov/files/document/fy-2025-icd-10-cm-coding-guidelines.pdf
- https://www.wolterskluwer.com/en/expert-insights/2025-icd10-code-updates
- https://hiacode.com/blog/new-icd-10-cm-codes
