Medical practices preparing for ICD-10-CM and CPT updates in 2026 should focus less on the sheer volume of new codes and more on where coding rules and condition-specific guidance have materially changed.

Several updates in the FY 2026 ICD-10-CM guidelines directly affect diagnosis selection, sequencing, and valid code combinations, with downstream impact on claims accuracy and reimbursement.

COVID-19 remains a focal area, but not the only one. Updated guidance reinforces exact code pairings when COVID-19 is documented with respiratory manifestations. Providers must differentiate between lower respiratory infections, unspecified respiratory infections, and defined conditions such as pneumonia or bronchitis, each requiring specific additional codes alongside the COVID-19 diagnosis. The guidelines also clarify proper use of post-COVID condition codes, particularly when symptoms persist after resolution versus when a new active infection is present. These distinctions affect principal diagnosis selection and payer validation.

Multisystem inflammatory syndrome (MIS) coding is further refined. The guidelines clearly distinguish coding scenarios based on whether MIS occurs during active COVID-19 infection, following a prior infection, or after exposure without confirmed infection. Each scenario requires a different sequencing approach to reduce ambiguity. But it increases the need for precise clinical documentation.

Beyond COVID-19, colonization and carrier status coding receive important clarification. The guidelines reinforce correct use of MRSA and MSSA carrier codes and confirm that colonization may be reported alongside an active infection when both are documented. This has implications for inpatient risk reporting, infection tracking, and outpatient documentation accuracy.

Vector-borne and emerging infectious diseases also see tighter rules. Zika virus coding is restricted to confirmed cases only. Suspected cases or exposures must be coded using symptom-based or exposure codes rather than the Zika diagnosis code itself. This change reduces inappropriate code assignment and aligns diagnosis reporting with laboratory confirmation.

Obstetric coding guidance includes clearer direction for post-abortion complications. Hemorrhage following an elective abortion must be coded using abortion-specific complication codes rather than general postpartum hemorrhage codes. This distinction directly affects diagnosis accuracy, reporting compliance, and audit risk for OB and surgical practices.

Newborn and perinatal coding guidance adds clarity for congenital and perinatal infections. When a newborn acquires COVID-19 in utero or during delivery, the guidelines specify using congenital infection codes in combination with COVID-19 diagnosis codes, while maintaining standard birth record sequencing. This guidance addresses prior inconsistencies in neonatal coding.

Preventive and prophylactic encounter coding is also reinforced. Encounters for prophylactic organ removal require the appropriate Z codes to be reported as first-listed diagnoses, with supporting risk-factor codes added as applicable. The guidelines clearly separate preventive services from treatment-driven encounters to reduce misclassification.

On the procedural side, CPT 2026 introduces over 288 new codes (418 changes in total) effective January 1, 2026, with direct implications for charge capture.

Remote physiologic and therapeutic monitoring services expand to include shorter monitoring periods and lower monthly time thresholds for treatment management. These changes allow more practices to report digital health services that previously fell below billing requirements.

AI-supported diagnostic services represent a growing area of CPT expansion. New codes capture the use of artificial intelligence in cardiovascular imaging, wound assessment, and diagnostic analytics. These services move from implicit components of care to explicitly billable procedures when documentation supports their use.

Moreover, major CPT code restructures affect certain procedural categories, including deletions and revised descriptors. Practices performing affected procedures must update charge masters and coding workflows to avoid denials or missed revenue under the new code set.

Taken together, the 2026 ICD-10-CM and CPT updates signal a continued shift toward tighter clinical specificity and technology-driven care models. Practices that focus on condition-level coding changes, rather than volume alone, will be best positioned to maintain compliance and protect revenue as we enter the new year.

For a deeper look at the FY 2026 ICD-10-CM guideline updates and the full scope of CPT 2026 code changes, please review the official ICD-10-CM coding guidelines and the latest CPT code update resources.