2026 ICD-10-CM Diagnosis Code T40.425SAdverse effect of tramadol, sequela
T40.425S is a billable ICD-10-CM diagnosis code for adverse effect of tramadol, 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. Coders also document this condition as adverse reaction caused by tramadol. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Mental and substance use disorders; sequela; and Poisoning/toxic effect/adverse effects/underdosing, sequela.
Code Identity
Code Classification
Code EditsBilling
Medicare Code Editor checks that affect claim validity for T40.425S.
Present on Admission (POA)Billing
T40.425S is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Adverse reaction caused by tramadol
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 narcotics and psychodysleptics [hallucinogens] (T40). 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.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Tramadol
a narcotic analgesic proposed for severe pain. it may be habituating.
Table of Drugs and ChemicalsClinical
Code History & ChangesHistory
Replacement T40.425S replaces the following previously assigned code(s):
- T40.4X5S - Adverse effect of other synthetic narcotics, sequela
Questions About T40.425SOverview
Is T40.425S (Adverse effect of tramadol) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report adverse effect of tramadol, sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character S in T40.425S mean?
The final character S makes this a sequela code: it reports a lingering problem that remains after the adverse effect of tramadol itself has resolved, not the original event.
What MS-DRG does T40.425S group to?
On inpatient claims, adverse effect of tramadol, 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 T40.425S be a principal diagnosis?
No. The Medicare Code Editor rejects this code as a principal diagnosis because adverse effect of tramadol, sequela describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.
Is T40.425S 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 tramadol, sequela on inpatient claims.
Footnotes
[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.
