ICD 10 CM Updates for 2025 Chapters 1-5
Welcome to Part One of an in depth review 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 1
There were no changes to chapter one. There was a revision of A77.41 revised to correct the spelling of “chaffeensis.”. This is the name given to a class of bacteria. The family of codes for Ehrlichiosis A77.4X refers to the general name used to describe diseases caused by the bacteria Ehrlichia chaffeensis, E. ewingii, or E. muris eauclairensis in the United States. These bacteria are disseminated primarily through the bite of infected ticks including the lone star tick (Amblyomma americanum) and the blacklegged tick (Ixodes scapularis). Symptoms of ehrlichiosis include fever, chills, headache, muscle aches, and can include an upset stomach. The treatment of choice for adults and children of all ages with ehrlichiosis is Doxycycline. About Ehrlichiosis | Ehrlichiosis | CDC
Chapter 2
The ICD 10 CM Coordination and Maintenance committee added over 35 codes for Lymphoma in remission and added a few new lymphoma classifications such as C86 Other specified types of T/NK cell lymphoma and C88 Malignant immunoproliferative disease and certain other B Cell Lymphoma. The new lymphoma in remission codes, C93.390 and C83.398 were assigned CC (Comorbidity /Complication) status.
Lymphoma is an extremely broad term that includes a variety of cancers originating in the lymphatic system. Hodgkin’s lymphoma and Non Hodgkin Lymphomas are the 2 main classifications for lymphoma. Hodgkin’s Lymphoma is confirmed on pathology with a finding of Hodgkin Reed – Sternberg Cells, which are from B cell origin. Non-Hodgkin lymphoma (NHL) includes more than 50 sub types. Diffuse large B Cell lymphoma (DLBCL) is the most common NHL, accounting for 25% to 30% of cases. It is a clinically aggressive lymphoma that usually arises in the lymph nodes but can also be present anywhere else in the body.
Lymphocytes are a type of white blood cell that play a critical role in our immune system. They are responsible for recognizing and attacking foreign cells, such as bacteria, viruses, and cancer cells.
There are three main subtypes of lymphocytes:
B cells: Produce antibodies to fight off infections. These are responsible for humoral immunity. Humoral immunity is also called antibody-mediated immunity. This physiological mechanism protects the body from pathogens and foreign substances in extracellular fluids using antibodies created in response to contact with a pathogen.
Humoral Immunity - The Definitive Guide | Biology Dictionary
T cells: These cells are responsible for cell mediated immunity. There are two types of T-Cells. Cytotoxic T cells go straight in to attack and kill infected or abnormal cells. Helper T Cells call in the multitude of additional components of the immune response by activating other immune cells to come in to combat the foreign cells.
Natural killer (NK) cells: These cells are part of the innate immune system and are the first line of defense. Their job is to destroy damaged or abnormal cells by providing a rapid response to threats. They patrol the body looking for cancer cells and viruses, which they promptly destroy.
Coders are taught not to code neoplasms based on a cell line but with lymphoma the cell line will drive the diagnosis.
The September 12-13, 2023, ICD 10 Coordination and Maintenance Meeting highlighted the proposal for adding the new codes, citing: “Lymphoma is a cancer of the lymphatic system, which is part of the body's germ-fighting network. The lymphatic system includes the lymph nodes (lymph glands), spleen, thymus gland and bone marrow. Lymphoma can affect all those areas as well as other organs throughout the body.1 In general, the goal of treatment is to destroy as many lymphoma cells as possible and to induce a complete remission. Complete remission means that all evidence of disease is eliminated. Patients who go into remission are sometimes cured of their disease.”
“A new ICD-10-CM code will provide coding specificity for the distinct types of lymphoma in remission. The absence of lymphoma in remission codes will hinder the ability to make meaningful comparisons to assess and evaluate differences in patient care, statistical data, resource consumption (i.e., overall length of stay, additional drugs, etc.), and accurate clinical outcomes of lymphoma cases. The National Center of Health Statistics received this proposal requesting new ICD-10-CM codes for lymphoma in remission from Alliance Dedicated Cancer Centers (ADCC).” Topic Packet September 2023 (cdc.gov)
Each category of Lymphoma code was assigned an additional code to denote the cancer was in remission with an A appended to the end of the code. The following is a sample of what can be found in the new ICD 10 CM code set for Lymphoma in remission.
C81.0A Nodular lymphocyte predominant Hodgkin lymphoma, in remission
C81.1A Nodular sclerosis Hodgkin lymphoma in remission
C81.2A Mixed cellularity Hodgkin lymphoma, in remission
C81.3A Lymphocyte depleted Hodgkin lymphoma, in remission
C82.0A Follicular lymphoma grade I, in remission
C82.1A Follicular lymphoma grade II, in remission
C83.0A Small cell B-cell lymphoma, in remission
C83.1A Mantle cell lymphoma, in remission
C83.3A Diffuse large B-cell lymphoma, in remission
A new code (C83.390 Primary central nervous system lymphoma) was added for Primary Central Nervous System Lymphoma (PCNSL). This is an aggressive extranodal form of Non-Hodgkin’s lymphoma which originates directly in the spinal cord, meninges, or brain. PCNSL was uniquely identifiable in ICD-9-CM with code 200.50, Primary central nervous system lymphoma, unspecified site, extranodal and solid organ sites. ICD-10-CM did not uniquely identify PCNSL, and a variety of codes were being assigned erroneously in an effort to code for this type of lymphoma. Codes used in error include C71.9, Malignant neoplasm of brain, unspecified; C72.9, Malignant neoplasm of central nervous system, unspecified; C83.39, Diffuse large B-cell lymphoma, extranodal and solid organ sites; and C83.89, Other non-follicular lymphoma, extranodal and solid organ sites. Adding a unique code for PCNSL in ICD-10-CM will ensure consistent identification of the disorder for accurate tracking and research efforts.
PCNSL is a rare disorder, comprising about 4-6% of extranodal lymphomas and 1% of all Non-Hodgkin’s. The cause of PCNSL is not known, it is under study. Approximately 90- 95%, are diffuse large B-cell lymphoma, and remaining cell types include lymphoblastic, T-cell, and Burkitt lymphomas.
The two new codes are as follows:
C83.390 Primary central nervous system lymphoma (this includes)
PCNSL of brain
PCNSL of meninges
PCNSL of spinal cord
PCNSL NOS
Excludes1: Primary central nervous system lymphoma, Burkitt (C83.79)
Primary central nervous system lymphoma, lymphoblastic (C83.59)
Primary central nervous system lymphoma, other (C83.89)
Primary central nervous system lymphoma, T-cell (C84.49)
C83.398 Diffuse large B-cell lymphoma of other extranodal and solid organ sites
Chapter 3
Just one new code D61.03 was assigned for Fanconi anemia. Fanconi anemia is the most common cause of inherited bone marrow failure due to a rare autosomal recessive genetic disorder involving all 3 blood cell lines. ICD 10 CM code D61.03 will help better identify patients with this rare condition. Patients with this diagnosis can be followed for treatment and research as it is a risk factor for multiple cancers. https://www.ncbi.nlm.nih.gov/books/NBK559133/
Chapter 4
Three new codes were added to Type 1 diabetes mellitus (E10), to identify presymptomatic diagnoses (E10.A-). Diabetes type 1 is a chronic autoimmune disease according to a Scientific Statement from September 15, 2015, from the Juvenile Diabetes Research Foundation, the Endocrine Society, and the American Diabetes Association. The statement defined the stages as follows: “Stage 1 is defined as the presence of β-cell autoimmunity as evidenced by the presence of two or more islet autoantibodies with normoglycemia and is presymptomatic, stage 2 as the presence of β-cell autoimmunity with dysglycemia and is presymptomatic, and stage 3 as onset of symptomatic disease. Adoption of this staging classification provides a standardized taxonomy for type 1 diabetes and will aid the development of therapies and the design of clinical trials to prevent symptomatic disease, promote precision medicine, and provide a framework for an optimized benefit/risk ratio that will impact regulatory approval, reimbursement, and adoption of interventions in the early stages of type 1 diabetes to prevent symptomatic disease.”
E10.A Type 1 diabetes mellitus, presymptomatic
E10.A0 Type 1 diabetes mellitus, presymptomatic, unspecified
E10.A1 Type 1 diabetes mellitus, presymptomatic, Stage 1
Multiple confirmed islet autoantibodies with normoglycemia
E10.A2 Type 1 diabetes mellitus, presymptomatic, Stage 2
Confirmed islet autoimmunity with dysglycemia
A new family of codes for hypoglycemia were added to ICD 10 CM for 2025. The new codes identify this diagnosis by levels of low blood sugar or alteration of mental or physical abilities. The 3 new codes are found under “Other disorders of pancreatic internal secretion”
In hypoglycemia level 1, blood glucose is lower than 70 mg/dL; patients accustomed to low blood glucose levels may be asymptomatic.
Hypoglycemia level 2, blood glucose is less than 54 mg/dL; patients may experience sweating, tremors, or loss of consciousness.
Hypoglycemia level 3, a blood glucose measurement is not required for this diagnosis, but hypoglycemia is severe enough to alter mentation or physical abilities, such that the patient requires assistance. Baseline function recovers if the patient can consume carbohydrates or glucagon.
Topic Packet September 2023 (cdc.gov)
A new directive was also added under E16.2
E16.2 Hypoglycemia, unspecified Add
Use additional code for hypoglycemia level, if applicable (E16.A-)
E16.A Hypoglycemia level
E16.A1 Hypoglycemia level 1
E16.A2 Hypoglycemia level 2
E16.A3 Hypoglycemia level 3
E34.0 Carcinoid syndrome
Code also the underlying disorder, such as:
primary neuroendocrine tumors (C7A.-) (C7A.0-C7A.098)
secondary neuroendocrine tumors (C7B.-) (C7B.0-C7B.09)
E34.00 Carcinoid syndrome, unspecified
Carcinoid disease, unspecified
E34.01 Carcinoid heart syndrome
Carcinoid heart disease
Hedinger syndrome
E34.00 Other carcinoid syndrome
Carcinoid disease NEC
Carcinoid syndrome NEC
Other carcinoid disease
There was a new family of codes added for Carcinoid syndrome. Carcinoid syndrome refers to a group of symptoms often caused by the systemic release of different kinds of circulating biologically active compounds, mostly from well-differentiated neuroendocrine tumors. Initially well-differentiated neuroendocrine tumors were known as carcinoid tumors, hence the name.
According to the National institute of Health the clinical presentation of this syndrome can include : “vasodilatory effects of biologically active amines, peptides, and prostaglandins (flushing, wheezing), gastrointestinal symptoms (diarrhea, malabsorption), pellagra (secondary to niacin deficiency), cardiac symptoms (right-sided valvular disease, mostly tricuspid regurgitation), fatigue, and sometimes cognitive impairment.[4]”
Carcinoid Syndrome - StatPearls - NCBI Bookshelf
Obesity classifications (E66.811-E66.813), were added as a new family of codes to designate Obesity based on BMI.
Obesity class I equals a BMI of 30 to less than 35.
Obesity class II equals a BMI of 35 to less than 40.
Obesity class III, also called severe obesity, equals a BMI of 40 or higher.
E74.82 Disorders of citrate metabolism
E74.820 SLC13A5 Citrate Transporter Disorder
E74.829 Other disorders of citrate metabolism
Citrate metabolism is a very complex topic and is influenced by multiple internal and external factors. Coders and CDI specialists without a PhD in Biochemistry will have to rely on provider documentation and or discussion for these new codes as a query could be challenging. The excerpts / explanation below from the National Institute of Health highlight some of the intricacies associated with citrate use in the human body. It also shows the genetic anomaly associated with citrate transportation in the body per ICD 10 CM code E74.820.
Citrate is an intermediate chemical found in the “Tricarboxylic Acid Cycle” (TCA cycle), a metabolic pathway. It is used by all aerobic (oxygen breathing) organisms to produce usable chemical energy. It is a derivative of citric acid, a weak organic acid which can be introduced with diet since it naturally exists in a variety of fruits (Orange juice) and vegetables and can be consumed as a dietary supplement.
In humans, citrate is produced in the mitochondria after the condensation of acetyl coenzyme A (acetylCoA) and oxaloacetate, which are catalyzed by citrate synthase. Citrate then enters the TCA cycle, hence becoming the primary adenosine 5′-triphosphate (ATP) provider by which living cells harvest the energy they need to accomplish essential and specific cellular functions [1]
There is a balance between citrate availability and elimination, depending on physiological requirements. Citrate balance depends on four pillars, which include nutritional intake, renal clearance, cellular metabolism, and bone remodeling.
The human gene SLC13A2 encodes the sodium-dicarboxylate cotransporter (NaDC1) which is highly expressed in the brush-border membranes of the renal proximal tubule and intestinal cells, and reabsorbs Krebs cycle intermediates, i.e., succinate and citrate [108].) Scientists have hypothesized that NaDC1 alterations could play a role in the development of kidney stones by affecting the citrate concentration in the urine [109]. The functional properties and protein expression of eight (genetic) coding region variants of NaDC1 have recently been characterized; the majority of them appeared to decrease transport activity and were predicted to result in decreased citrate absorption in the intestine and kidney [110]. Even if not investigated, it is reasonable to assume that effects on bone mass may occur since these conditions influence citrate metabolism and predispose to renal stone formation as well. https://pmc.ncbi.nlm.nih.gov/articles/PMC6893553/
E88.82 Obesity due to disruption of MC4R pathway
Use additional code, if applicable, to identify associated manifestations, such as polyphagia (R63.2) (R63.2)
Use additional code to identify body mass index (BMI), if known (Z68.-) (Z68.1-68.56)
This new ICD 10 code E88.82was added to identify a disruption in the MC4R pathway associated with obesity. Genetic studies to support this diagnosis should be referenced in clinical records.
According to the Application of Clinical Genetics 2019, Jun 5;12:87–93. “Body weight is determined by the balance between food intake and energy expenditure.4 The hypothalamus regulates both aspects in response to cues from peripheral hormones (such as leptin [LEP] or ghrelin) that reflect the nutritional state. Within the hypothalamus, the melanocortin-4 receptor (MC4R) pathway, which is a component of the central melanocortin pathway, regulates satiety and energy utilization.”
The same article indicated the following: “The TEMPO registry (NCT03479437) is a voluntary, prospective, open-ended registry of individuals with rare genetic disorders of obesity due to mutations in genes within the MC4R pathway who have early-onset severe obesity.”
Chapter 5
Beginning in October 2024 there were 26 new codes added to Chapter 5 for Mental, Behavioral and Neurodevelopmental Disorders in ICD 10 CM. FY 2025 ICD-10-CM Code Updates (hiacode.com).
Anorexia Nervosa is categorized based on whether the patient restricts food intake or binges and purges. Patients who over the last 3 months have lost weight by dieting, fasting or excessive exercise are classified as having Anorexia Nervosa Restrictive Type. Anorexia Nervosa Binge Eating / Purging Type is diagnosed in individuals who engage in recurrent episodes of binge eating followed by self-induced vomiting, or misuse of laxatives, diuretics or enemas.
The four severity categories for anorexia nervosa are based on Body Mass Index:
Mild: >= 17.0 kg/m2
Moderate: 16-16.99 kg/m2
Severe: 15-15.99 kg/m2
Extreme: < 15 kg/m2
F50.01 Anorexia Nervosa, restricting type
F50.010 Anorexia nervosa, restricting type, Mild
F50.011 Anorexia nervosa, restricting type, Moderate
F50.012 Anorexia nervosa, restricting type, Severe
F50.013 Anorexia nervosa, restricting type, Extreme
F50.014 Anorexia nervosa, restricting type, in remission
Anorexia nervosa, restricting type, in full remission
OR
Anorexia nervosa, restricting type, in partial remission
F50.019 Anorexia nervosa, restricting type, Unspecified
F50.02 Anorexia nervosa, Binge-eating/purging type,
F50.020 Anorexia nervosa, Binge-eating/purging type, Mild
F50.021 Anorexia nervosa, Binge-eating/purging type, Moderate
F50.022 Anorexia nervosa, Binge-eating/purging type, Severe
F50.023 Anorexia nervosa, Binge-eating/purging type, Extreme
F50.024 Anorexia nervosa, Binge-eating/purging type, in remission
Anorexia nervosa, binge eating/purging type, in full remission
Anorexia nervosa, binge eating/purging type, in partial remission
F50.029 Anorexia nervosa, Binge-eating/purging type, Unspecified
Bulimia Nervosa is defined as follows: Consuming an amount of food, in a defined amount of time (e.g., within any 1-hour period), that is larger than what most people would eat in a similar period of time under similar circumstances. Patients will then compensate to prevent weight gain by inducing vomiting, taking diuretics, abusing laxatives and fasting or exercising in excess. Providers look for these behaviors to occur on average at least once per week for 3 weeks. Patient history will describe feeling out of control while this is happening and having a view of themselves unjustly influenced based on body shape and weight.
Severity for Bulima Nervosa is based on the number of compensatory behaviors per week.
Mild: An average of 1-3 episodes per week
Moderate: An average of 4-7 episodes per week
Severe: An average of 8-13 episodes per week
Extreme: An average of 14 or more episodes per week
F50.2 Bulimia Nervosa
F50.21 Mild
F50.22 Moderate
F50.23 Severe
F50.24 Extreme
F50.25 In partial remission
F50.25 In full remission
F50.20 Unspecified
According to the National Institute of Mental Health: “Binge-eating disorder is a condition where people lose control over their eating and have reoccurring episodes of eating unusually large amounts of food. Unlike bulimia nervosa, periods of binge-eating are not followed by purging, excessive exercise, or fasting. As a result, people with binge-eating disorder often are overweight or obese. Binge-eating disorder is the most common eating disorder in the U.S” Eating Disorders - National Institute of Mental Health (NIMH)
The severity of Binge eating disorder is based on the number of binging episodes per week.
Mild: An average of 1-3 episodes per week
Moderate: An average of 4-7 episodes per week
Severe: An average of 8-13 episodes per week
Extreme: An average of 14 or more episodes per week
F50.81 Binge Eating Disorder
F50.810 Binge eating disorder, mild
F50.811Binge eating disorder, moderate
F50.812 Binge eating disorder, severe
F50.813 Binge eating disorder, extreme
F50.814 Binge eating disorder, in remission
F50.819 Binge eating disorder, unspecified
Pica in adults is defined as relentless eating of nonnutritive, nonfood substances over a period of at least 1 month. Pica definitions further describe eating of nonnutritive, nonfood substances as inappropriate to the developmental level of the patient. The alternative eating behavior is not supported culturally or consistent with normal social practices. If Pica occurs in the context of other mental or medical conditions, it requires additional clinical attention.
F50.83 Pica in adults
Rumination disorder is identified by repeated regurgitation of food over a period of at least 1 month. The regurgitation of food is not associated with a medical condition such as gastroesophageal reflux (GERD) or pyloric stenosis or hiatal hernia. The food that is regurgitated can be re-chewed, re-swallowed, or spit out. There is also no association between Rumination Disorder and other psychiatric eating disorders. If Rumination Disorder occurs in the context of other mental or medical conditions, it requires additional clinical attention. dsm-5 criteria.pdf
F50.84 Rumination disorder in adults
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