2026 ICD-10-CM Diagnosis Code T36.AX5SAdverse effect of fluoroquinolone antibiotics, sequela
T36.AX5S is a billable ICD-10-CM diagnosis code for adverse effect of fluoroquinolone antibiotics, sequela. The 7th character S marks it as a sequela code, which reports a problem that remains after the original condition has resolved. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 922 through 923. The code is not accepted as a principal diagnosis by the Medicare Code Editor and exempt from POA reporting.
Code Identity
Code Classification
Code EditsBilling
Medicare Code Editor checks that affect claim validity for T36.AX5S.
Present on Admission (POA)Billing
T36.AX5S is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.
Coding GuidelinesGuidance
When coding an adverse effect of a drug that has been correctly prescribed and properly administered, assign the appropriate code for the nature of the adverse effect followed by the appropriate code for the adverse effect of the drug.
The appropriate 7th character is to be added to each code from block Poisoning by, adverse effect of and underdosing of systemic antibiotics (T36). Use the following options for the applicable episode of care:
- A - initial encounter
- D - subsequent encounter
- S - sequela
Source: ICD-10-CM Official Guidelines for Coding and Reporting, FY 2026, published by CMS and the National Center for Health Statistics.
Table of Drugs and ChemicalsClinical
Code History & ChangesHistory
New Code T36.AX5S was added to the ICD-10-CM code set for FY 2026, effective October 1, 2025.
Replacement T36.AX5S replaces the following previously assigned code(s):
- T36.8X5S - Adverse effect of other systemic antibiotics, sequela
Questions About T36.AX5SOverview
Is T36.AX5S (Adverse effect of fluoroquinolone antibiotics) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report adverse effect of fluoroquinolone antibiotics, sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character S in T36.AX5S mean?
The final character S makes this a sequela code: it reports a lingering problem that remains after the adverse effect of fluoroquinolone antibiotics itself has resolved, not the original event.
What MS-DRG does T36.AX5S group to?
On inpatient claims, adverse effect of fluoroquinolone antibiotics, sequela maps to MS-DRG 922, 923, with relative weights from 1.0177 to 1.7494 depending on complications. Higher weights mean higher Medicare reimbursement.
Can T36.AX5S be a principal diagnosis?
No. The Medicare Code Editor rejects this code as a principal diagnosis because adverse effect of fluoroquinolone antibiotics, sequela describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.
Is T36.AX5S exempt from POA reporting?
Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for adverse effect of fluoroquinolone antibiotics, sequela on inpatient claims.
