The FY 2027 ICD-10-CM code set took effect on October 1, 2026. CMS posted the updates in June. The guidelines barely changed, but the Tabular List changed a lot. Beyond the big expansions, a group of smaller additions covers cancer syndromes, platelet disorders, cardiomyopathies, post-surgical complications, low BMI, and more. They are easy to overlook, and they matter for accurate coding.
What changed in ICD-10-CM for fiscal year 2027?
The new codes went live on October 1, 2026. Most of the work landed in the Tabular List, while the official guidelines saw only minor edits.
The largest additions involve arrhythmias, plantar fasciitis, plantar fascial fibromatosis, osteomyelitis, ectopic pregnancies, vanishing twin syndrome, toxic effects of drugs, and military-related exposures. Those get most of the attention.
This article looks at the smaller changes instead. These conditions got only a handful of new codes each, but the added detail lets you describe a patient’s condition or circumstances more precisely. For background, see the minutes of the March 2026 ICD-10 Coordination and Maintenance Committee Meeting.
Quick reference: new codes covered in this article
| Code | Condition |
|---|---|
| C78.3- (new codes) | Secondary malignant neoplasm of larynx, pharynx, and oral cavity |
| QA1.71 | Lynch syndrome |
| QA1.790 | Familial cancer syndrome with pathogenic BRCA1 mutation |
| QA1.791 | Familial cancer syndrome with pathogenic BRCA2 mutation |
| QA1.792 | Li-Fraumeni syndrome |
| D69.11 | Glanzmann thrombasthenia |
| D69.19 | Other qualitative platelet defects |
| E89.83- | Postprocedural hypoglycemia |
| N99.860 | Intraoperative and postprocedural nipple ischemia |
| N99.861 | Intraoperative and postprocedural nipple necrosis |
| I42.01 | Familial-genetic dilated cardiomyopathy |
| I42.81 | Arrhythmogenic cardiomyopathy |
| J34.83- | Odontogenic sinusitis |
| J4B | Pulmonary mycetoma |
| K31.B | Hypertrophic pyloric stenosis, in childhood |
| K6A.01 | Prevesical abscess |
| K76.83 | Intestinal failure-associated liver disease |
| M04.3 | VEXAS syndrome |
| Q87.A | Loeys-Dietz syndrome |
| R78.72 | Gadolinium in blood |
| Z77.013 | Contact with and suspected exposure to gadolinium |
| Z68.18 / Z68.19 | Adult BMI 18.4 or less / 18.5 to 19.9 |
| Z86.17 | Personal history of Clostridioides difficile infection |
| Z87.890- / Z87.893 | Personal history of gender transition / detransition |
Malignant neoplasms
Which new code identifies secondary cancers of the larynx, pharynx, and oral cavity?
New codes in subcategory C78.3- (secondary malignant neoplasm of other and unspecified respiratory organs) now cover these sites. Secondary tumors here can be more serious than primary ones because they affect speech and swallowing, and patients may need a speech-language pathologist. Specific codes make that clinical picture easier to document.
What is the new code for Lynch syndrome?
Lynch syndrome now has its own code, QA1.71. It is the most common cause of inherited colorectal and endometrial cancer. Patients can develop cancer younger, so earlier and more frequent colorectal screening is generally recommended. Reporting this code can help support medical necessity for enhanced surveillance.
What are the new BRCA1 and BRCA2 codes?
Hereditary breast and ovarian cancer syndrome is caused by a BRCA1 or BRCA2 mutation. It raises the risk of cancers of the fallopian tubes, peritoneum, prostate, pancreas, and male breast. Two new codes separate the mutations:
- QA1.790: familial cancer syndrome with pathogenic BRCA1 mutation
- QA1.791: familial cancer syndrome with pathogenic BRCA2 mutation
Is there a code for Li-Fraumeni syndrome?
Yes. QA1.792 identifies Li-Fraumeni syndrome (LFS). People with LFS face a higher risk of premenopausal breast cancer, sarcomas, brain tumors, leukemia, and adrenocortical carcinoma.
Bleeding disorders
Two new codes describe platelet function problems more precisely:
- D69.11: Glanzmann thrombasthenia
- D69.19: other qualitative platelet defects, including Bernard-Soulier syndrome and gray platelet syndrome
Postoperative and postprocedural conditions
How do you code hypoglycemia after bariatric surgery?
Postprocedural hypoglycemia can develop after bariatric surgery and cause repeated, debilitating low blood sugar episodes. It is thought to result from hormonal and glucose changes caused by altered nutrient transit. Subcategory E89.83- lets you specify post-bariatric hypoglycemia and post-Nissen fundoplication hypoglycemia.
What are the codes for nipple ischemia and necrosis?
Both can occur after breast cancer surgery.
- N99.860: intraoperative and postprocedural nipple ischemia, where blood flow to the nipple is insufficient
- N99.861: intraoperative and postprocedural nipple necrosis, where severe or prolonged loss of blood flow leads to tissue loss
Cardiovascular system
Dilated cardiomyopathy (DCM) is the most common form of cardiomyopathy. The heart chambers enlarge, and the muscle stretches and weakens, so the heart pumps less effectively.
- I42.01 identifies familial-genetic DCM. Patients with a genetic cause tend to progress to end-stage heart failure and death faster than those with DCM unrelated to genetic variants.
- I42.81 identifies arrhythmogenic cardiomyopathy (ACM), also called arrhythmogenic right ventricular cardiomyopathy (ARVC). Normal heart muscle is replaced with fibrofatty tissue, which can lead to ventricular arrhythmias and sudden cardiac death.
Respiratory system
What is odontogenic sinusitis, and how is it coded?
Odontogenic sinusitis is sinus inflammation that starts from a dental source, such as a tooth infection or an injury during a dental procedure. New subcategory J34.83- has codes by affected sinus: maxillary, ethmoid, frontal, and sphenoid. A separate code applies when the sinus is unspecified.
What is the code for pulmonary mycetoma?
J4B now reports pulmonary mycetoma. This is a clump of fungal material and debris growing inside an existing lung cavity, which may come from tuberculosis, sarcoidosis, or a lung abscess. Aspergillus is the most common fungus involved.
Digestive system
- K31.B covers hypertrophic pyloric stenosis in childhood, also known as infantile hypertrophic pyloric stenosis (IHPS). The pylorus, the opening between the stomach and small intestine, becomes abnormally thick. Food cannot leave the stomach normally, which causes gastric outlet obstruction in infants.
- K6A.01 reports a prevesical abscess, a pocket of pus in the space between the bladder and the pubic bone.
- K76.83 identifies intestinal failure-associated liver disease (IFALD). It can develop in patients on long-term parenteral nutrition and may cause bile backup, fat buildup in the liver, and scarring.
Musculoskeletal system and connective tissue
- M04.3 reports VEXAS syndrome (vacuoles, E1 ubiquitin-activating enzyme, X-linked, autoinflammatory, somatic mutations). This rare autoinflammatory disorder mainly affects middle-aged and older men. It can cause widespread inflammation, including painful skin rashes, pain and swelling in the ears and nose, cough, shortness of breath, and severe blood vessel inflammation.
- Q87.A reports Loeys-Dietz syndrome, a rare genetic connective tissue disorder. It can cause aortic root aneurysms, twisted blood vessels, craniofacial differences, scoliosis, clubfoot, and translucent, easily bruised skin.
Abnormal findings: gadolinium
Gadolinium is a rare earth metal used in some MRI contrast agents to make images clearer. High levels in the body may be linked to symptoms like bone pain and muscle weakness. Two new codes cover it from different angles:
- R78.72: gadolinium found in the blood
- Z77.013: contact with and suspected exposure to gadolinium
Z codes
What are the new low BMI codes?
Low BMI is linked to higher risk of poor surgical outcomes, postoperative infection, severe respiratory infection, and fertility problems. Until now, Z68.1 was the lowest option and covered every adult BMI of 19.9 or less. It is now split in two:
- Z68.18: BMI 18.4 or less, adult
- Z68.19: BMI 18.5 to 19.9, adult
How do you report a history of C. diff?
Z86.17 captures a personal history of Clostridioides difficile infection. C. diff can cause anything from diarrhea to severe, life-threatening colitis. It often follows antibiotic use and is especially common in older adults and in hospitals and long-term care facilities. A prior infection raises the risk of recurrence and can influence future antibiotic choices, so the history is worth recording.
What are the new gender transition history codes?
People with gender dysphoria may pursue social, medical, or surgical steps as part of a transition. Social transition means non-surgical, non-drug changes, such as using a new name or binding the chest. Some people later accept their biological sex, which is called remission or desistance of gender dysphoria. Others have post-transition distress, such as grief, regret, self-hatred, or isolation, or choose to detransition by stopping or reversing parts of the transition.
New codes capture these situations:
- Z87.890-: personal history of social, medical, and surgical gender transition
- Z87.893: personal history of gender detransition
Frequently asked questions
When did the FY 2027 ICD-10-CM codes take effect? October 1, 2026. CMS posted the updates in June.
Did the official coding guidelines change for FY 2027? Only slightly. Most changes were made to the Tabular List.
Where can I read the background on these changes? In the minutes of the March 2026 Coordination and Maintenance Committee Meeting.
Why do small code additions matter? They let you record a condition or circumstance with more precision, which supports accurate reporting and, in some cases, medical necessity.
