ICD 10 CM Updates for 2025 Chapters 19-21
Welcome to Part Four, the final synopsis of this year’s new ICD 10 CM diagnoses codes. Coders and CDI specialists rely on provider documentation to assign codes. More often than not third party denials and appeals rely on clinical evidence to support the assigned diagnosis. This article provides both the coding and clinical evidence to support the new ICD 10 CM codes.
Chapter 19. Injury, Poisoning and Certain Other Consequences of External Causes
T45.A Poisoning by, adverse effect of and underdosing of immune checkpoint inhibitors and immunostimulant drugs
T45.AX Poisoning by, adverse effect of and underdosing of immune checkpoint inhibitors and immunostimulant drugs
T45.AX1 Poisoning by immune checkpoint inhibitors and immunostimulant drugs, accidental (unintentional)
T45.AX1A Poisoning by immune checkpoint inhibitors and immunostimulant drugs, accidental (unintentional), initial encounter
T45.AX1D Poisoning by immune checkpoint inhibitors and immunostimulant drugs, accidental (unintentional), subsequent encounter
T45.AX1S Poisoning by immune checkpoint inhibitors and immunostimulant drugs, accidental (unintentional), sequela
T45.AX2 Poisoning by immune checkpoint inhibitors and immunostimulant drugs, intentional self-harm
T45.AX2A Poisoning by immune checkpoint inhibitors and immunostimulant drugs, intentional self-harm, initial encounter
T45.AX2D Poisoning by immune checkpoint inhibitors and immunostimulant drugs, intentional self-harm, subsequent encounter
T45.AX2S Poisoning by immune checkpoint inhibitors and immunostimulant drugs, intentional self-harm, sequela
T45.AX3 Poisoning by immune checkpoint inhibitors and immunostimulant drugs, assault
T45.AX3A Poisoning by immune checkpoint inhibitors and immunostimulant drugs, assault, initial encounter
T45.AX3D Poisoning by immune checkpoint inhibitors and immunostimulant drugs, assault, subsequent encounter
T45.AX3S Poisoning by immune checkpoint inhibitors and immunostimulant drugs, assault, sequela
T45.AX4 Poisoning by immune checkpoint inhibitors and immunostimulant drugs, undetermined
T45.AX4A Poisoning by immune checkpoint inhibitors and immunostimulant drugs, undetermined, initial encounter
T45.AX4D Poisoning by immune checkpoint inhibitors and immunostimulant drugs, undetermined, subsequent encounter
T45.AX4S Poisoning by immune checkpoint inhibitors and immunostimulant drugs, undetermined, sequela
T45.AX5 Adverse effect of immune checkpoint inhibitors and immunostimulant drugs
T45.AX5A Adverse effect of immune checkpoint inhibitors and immunostimulant drugs, initial encounter
T45.AX5D Adverse effect of immune checkpoint inhibitors and immunostimulant drugs, subsequent encounter
T45.AX5S Adverse effect of immune checkpoint inhibitors and immunostimulant drugs, sequela
T45.AX6 Underdosing of immune checkpoint inhibitors and immunostimulant drugs
T45.AX6A Underdosing of immune checkpoint inhibitors and immunostimulant drugs, initial encounter
T45.AX6D Underdosing of immune checkpoint inhibitors and immunostimulant drugs, subsequent encounter
T45.AX6S Underdosing of immune checkpoint inhibitors and immunostimulant drugs, sequela
Twenty-six new codes were added to Chapter 19, Injury, Poisoning and Certain Other Consequences of External Causes for adverse effects of immune checkpoint inhibitors.
Checkpoint inhibitors don't kill cancer cells directly. They work by helping the immune system find and attack the cancer cells, wherever they are in the body.
Medicines that target different checkpoint proteins are now used to treat many types of cancer. All of these drugs can be given as an infusion into a vein (IV). Some of them can now be given as an injection under the skin (subcutaneously) over several minutes.
There are different types of checkpoint inhibitors depending on where they interact on the cells. Cancer cells mask their presence with proteins that turn off the body’s ability to identify them as “other” helping them to fly under the body’s normal immune response. Immune check point inhibitors block cancer cells from doing this and allows the body to attack the cancer cells.
Drugs you may be familiar with include Pembrolizumab (Keytruda), Nivolumab (Opdivo), Cemiplimab (Libtayo), Atezolizumab (Tecentriq and Tecentriq Hybreza), Avelumab (Bavencio), and Durvalumab (Imfinzi).
Some of the more common side effects of checkpoint inhibitors include Diarrhea, Fatigue, Cough, Nausea, Skin rash, Poor appetite, Constipation, and Muscle and joint pain.
Wound Dehiscence
There were 16 additions for disruption of operative wounds to identify their episode of care and the area involved.
T81.320 Disruption or dehiscence of gastrointestinal tract anastomosis, repair, or closure
T81.320A Disruption or dehiscence of gastrointestinal tract anastomosis, repair, or closure, initial encounter
T81.320D Disruption or dehiscence of gastrointestinal tract anastomosis, repair, or closure, subsequent encounter
T81.320S Disruption or dehiscence of gastrointestinal tract anastomosis, repair, or closure, sequela
T81.321 Disruption or dehiscence of closure of internal operation (surgical) wound of abdominal wall muscle or fascia
T81.321A Disruption or dehiscence of closure of internal operation (surgical) wound of abdominal wall muscle or fascia, initial encounter
T81.321D Disruption or dehiscence of closure of internal operation (surgical) wound of abdominal wall muscle or fascia, subsequent encounter
T81.321S Disruption or dehiscence of closure of internal operation (surgical) wound of abdominal wall muscle or fascia, sequela
T81.328 Disruption or dehiscence of closure of other specified internal operation (surgical) wound
T81.328A Disruption or dehiscence of closure of other specified internal operation (surgical) wound, initial encounter
T81.328D Disruption or dehiscence of closure of other specified internal operation (surgical) wound, subsequent encounter
T81.328S Disruption or dehiscence of closure of other specified internal operation (surgical) wound, sequela
T81.329 Deep disruption or dehiscence of operation wound, unspecified
T81.329A Deep disruption or dehiscence of operation wound, unspecified, initial encounter
T81.329D Deep disruption or dehiscence of operation wound, unspecified, subsequent encounter
T81.329S Deep disruption or dehiscence of operation wound, unspecified, sequela
Chapter 17. Congenital Malformations, Deformations and Chromosomal Abnormalities
Genetic Susceptibility and Hormone Receptors
Z15.1 Genetic susceptibility to epilepsy and neurodevelopmental disorders
Unacceptable Principal Dx (Inpatient Only)
Z15.2 Genetic susceptibility to obesity
Unacceptable Principal Dx (Inpatient Only)
Z17.2 Progesterone receptor status
Z17.21 Progesterone receptor positive status
Z17.22 Progesterone receptor negative status
Z17.3 Human epidermal growth factor 2 receptor
Z17.31 Human epidermal growth factor receptor 2 positive status
Z17.32 Human epidermal growth factor receptor 2 negative status
Z17.4 Combined receptor status
Z17.41 Hormone receptor positive
Z17.410 Hormone receptor positive with human epidermal growth factor receptor 2 positive status
Z17.411 Hormone receptor positive with human epidermal growth factor receptor 2 negative status
Z17.42 Hormone receptor negative
Z17.420 Hormone receptor negative with human epidermal growth factor receptor 2 positive status
Z17.421 Hormone receptor negative with human epidermal growth factor receptor 2 negative status
Human epidermal growth factor receptor 2 (HER2)-positive and hormone receptor-positive breast cancer is a well promoted concept in the diagnosing and treating breast cancer. The backbone of treatment for HR-positive HER2-positive tumors, is chemotherapy with anti -HER2 agents. Amplification and/or overexpression of the human epidermal growth factor 2 (HER2) oncogene occurs in about 15% of invasive breast cancers, and enables key activation of growth factor signaling and triggering breast cancer cell survival, proliferation, and invasion [1, 2]. Tumors with HER2 amplification and/or overexpression—also called HER2-positive breast cancer—are distinguished by poor clinical prognostic features, which translate into aggressive tumor behavior [1] and, importantly, by experimental and clinical resistance to endocrine therapy. Tracking and identifying this along with treatment outcomes will be integral to combating breast cancer. Human epidermal growth factor receptor 2 (HER2)-positive and hormone receptor-positive breast cancer: new insights into molecular interactions and clinical implications - ScienceDirect
Encounters
Z51.A Encounter for sepsis aftercare
Z59.71 Insufficient health insurance coverage
Z59.72 Insufficient welfare support
Duffy Antigens
Z67.A Duffy phenotype
Z67.A1 Duffy null
Unacceptable Principal Dx (Inpatient Only)
Z67.A2 Duffy a positive
Unacceptable Principal Dx (Inpatient Only)
Z67.A3 Duffy b positive
Unacceptable Principal Dx (Inpatient Only)
Z67.A4 Duffy a and b positive
Unacceptable Principal Dx (Inpatient Only)
The Duffy blood group was discovered in 1950, as a minor antigen on red blood cells. Duffy A and B have long been known to cause blood transfusion reactions. The Duffy Antigen and Duffy-null Phenotype are associated with protection against P. vivax malaria.
Scientists have known for decades that those of African ancestry have lower Absolute Neutrophil Count (ANC) without any increased risk for infection previously called ‘Benign Ethnic Neutropenia (BEN)’). BEN is associated with the Duffy-null phenotype where the Neutrophils migrate out of blood into tissues creating what looks like “neutropenia” but this is misleading as it is not a true neutropenia because the total body neutrophil count (TBNC) is normal. The desire was to track these patients due to the inappropriate diagnosis and extensive and unnecessary work up that follows.
Previously the Duffy antigen only had ICD-10-CM codes related to its ability to cause blood transfusion incompatibility and reactions and nothing to track BEN associated with the Duffy-null phenotype. Duffy db.pdf
Pediatric BMI Codes
Z68.55 Body mass index [BMI] pediatric, 120% of the 95th percentile for age to less than 140% of the 95th percentile for age
CC - Comorbidity or Complication (Inpatient Only)
Unacceptable Principal Dx (Inpatient Only)
Z68.56 Body mass index [BMI] pediatric, greater than or equal to 140% of the 95th percentile for age
CC - Comorbidity or Complication (Inpatient Only)
Unacceptable Principal Dx (Inpatient Only)
Childhood-specific Percentile-based BMI classifications were requested because the use of adult cut-offs in children leads to incorrect categorization of weight status.
Personal and Family History of Colon Polyps
Z83.72 Family history of familial adenomatous polyposis
Unacceptable Principal Dx (Inpatient Only)
Z86.0100 Personal history of colon polyps, unspecified
Z86.0101 Personal history of adenomatous and serrated colon polyps
Z86.0102 Personal history of hyperplastic colon polyps
Z86.0109 Personal history of other colon polyps
Personal History of Immune Checkpoint Inhibitor Therapy
Z92.26 Personal history of immune checkpoint inhibitor therapy
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