Proposed changes to the ICD-10-CM code set include new codes for personal history of Clostridiodes difficile (C. diff) infection, a low body mass index and more.
 
The update, which includes 184 new codes, 30 invalidated codes and four revised codes, was released Friday, April 10, as part of the Medicare fiscal year 2027 Hospital Inpatient PPS (IPPS) proposed rule. If finalized, the changes will take effect Oct. 1, 2026.
 
Found in Chapter 21: Factors influencing health status and contact with health services (Z00-Z99), a new code will be added for  Z86.17 (Personal history of Clostridioides difficile infection).
 
History of C. diff should be useful to home health agencies in particular, notes Brandi Whitemyer, an Ohio-based home health and coding expert. "We see a lot of patients with resolved C. diff and there is no good code to capture this currently, but the patients are at risk for reinfection, complications, rehospitalization, further GI complications, etc." 
 
Also helpful for both home health and hospice providers: new Z codes for body mass index (BMI):
  • Z68.18 (BMI 18.4 or less, adult)
  • Z68.19 (BMI 18.5-19.9, adult)
"We only use these when there is a diagnosed nutritional deficit or similar disorder (anorexia, cachexia, nutritional marasmus, etc.), but lower BMI is associated with higher risk for skin breakdown, immunodeficiency and other poor outcomes and when able to be calculated along with a disorder, should be captured," Whitemyer says. 
 
An expansion of cardiomyopathy codes I42.0 and I42.8 will allow reporting of familial-genetic dilated cardiomyopathy and arrhythmogenic cardiomyopathy. A new code, I47.22, tracks catecholaminergic polymorphic ventricular tachycardia (CPVT), a condition in which a structurally normal heart lapses into dangerous, irregular heart rhythms during stress or exercise. Also, look for new codes for other heart arrhythmias, including Brugada syndrome (I49.81) and ventricular bigeminy (I49.82).
 
Some agencies don't see patients with highly detailed cardiac medical records, but Whitemyer notes there are those that do and documentation from physicians has become increasingly specific for many conditions, including cardiomyopathies.
 
A new code for moderate hepatic fibrosis (K74.0A) allows more accurate coding of the liver disorder. This will be helpful since there are currently only codes for unspecified, early and advanced, Whitemyer notes.
 
Stage F2  is considered moderate by clinical classification, but this is currently included under early within the code set (under includes for K74.01), she says. "The moderate stage code will be more accurate."
 
Other notable changes
 
The proposed FY 2027 ICD-10-CM code set will delete C75.9 (Malignant neoplasm of endocrine gland, unspecified) and add three new codes to describe cancers of the oral cavity and throat.
  • C78.31 (Secondary malignant neoplasm of larynx).
  • C78.32 (Secondary malignant neoplasm of pharynx).
  • C79.83 (Secondary malignant neoplasm of oral cavity).
New endocrine codes E89.830 and E89.838 allow tracking of hypoglycemia occurring after bariatric and other surgeries.
 
Providers will have five new codes for sinusitis related to dental infections, damage and procedures, such as implants. Four codes will describe the specific sinus, with a fifth code for use when the provider doesn’t specify the sinus.
  • J34.830 (Odontogenic sinusitis, maxillary sinus).
  • J34.831 (Odontogenic sinusitis, ethmoid sinus).
  • J34.832 (Odontogenic sinusitis, frontal sinus).
  • J34.833 (Odontogenic sinusitis, sphenoid sinus).
  • J34.839 (Odontogenic sinusitis, unspecified).
According to a 2018 article in Laryngoscope – Investigative Otolaryngology, an estimated 10% of sinusitis cases are linked to dental issues.
 
Also, look for new digestive system codes for prevesical pelvic abscess (K6A.01) and other pelvic abscesses and diseases not elsewhere specified.
 
In the musculoskeletal chapter, expanded codes for plantar fasciitis (M67.A-) and plantar fascial fibromatosis (M72.2-) as well as other osteomyelitis (M86.8X-), will allow coding specific to laterality. A new code, M04.3 reports the severe, adult onset autoinflammatory disease known as VEXAS syndrome.
 
New genitourinary codes report intraoperative and post-procedural nipple ischemia (N99.860) and necrosis (N99.861).
 
New congenital codes will report familial cancer syndrome with pathogenic BRCA1 (QA1.790) and BRCA2 (QA1.791).
 
Another proposed ICD-10-CM update adds new war-related codes in Chapter 21:
  • Z77.32 (Contact with and [suspected] exposure to burn pits in war theater).
  • Z77.33 (Contact with and [suspected] exposure to Agent Orange).
The U.S. Department of Veterans Affairs lists a variety of cancers and pulmonary conditions as presumptive conditions associated with exposure to burn pits.