ICD-10-CM 2027 diagnosis code
T65.854DToxic effect of medetomidine, undetermined, subsequent encounter
T65.854D is a valid, billable ICD-10-CM code for toxic effect of medetomidine, undetermined, subsequent encounter. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.Short description: Toxic effect of medetomidine, undetermined, subs
Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS, effective October 1, 2026. Updated September 29, 2026. About our data
About T65.854D
T65.854D is the ICD-10-CM diagnosis code for toxic effect of medetomidine, undetermined, subsequent encounter. It belongs to category T65 (toxic effect of other and unspecified substances), block T51-T65 (toxic effects of substances chiefly nonmedicinal as to source) and chapter 19 (injury, poisoning and certain other consequences of external causes). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.
The 7th character "D" means subsequent encounter: use it for encounters after active treatment, while the patient is healing or recovering.
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 949 (Aftercare with CC/MCC, relative weight 1.123) and DRG 950 (Aftercare without CC/MCC, relative weight 0.7664), in MDC 23 (Factors Influencing Health Status and Other Contacts with Health Services), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
It is exempt from present-on-admission (POA) reporting, so no POA indicator is required.
It was added in FY2027, effective October 1, 2026.
7th character
Dsubsequent encounter
Other encounter types for T65.854:
Notes that apply from higher levels
Instructions written at a parent level also apply to T65.854D.
Broader instructions also apply from T51-T65 Toxic effects of substances chiefly nonmedicinal as to source and Chapter 19: Injury, poisoning and certain other consequences of external causes.
MS-DRG v44.0 grouping
All DRGs →Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.
MDC 23 · Factors Influencing Health Status and Other Contacts with Health Services
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2027 (effective 10/1/2026): Added
Common questions about T65.854D
Is T65.854D billable?
- Yes. T65.854D is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
What does the "D" at the end of T65.854D mean?
- It is the 7th character for subsequent encounter. Per the official guidelines, use it for encounters after active treatment, while the patient is healing or recovering.
Can T65.854D be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict T65.854D as a principal diagnosis.
Is T65.854D a CC or MCC?
- No. T65.854D is neither a CC nor an MCC under MS-DRG v44.0.
What DRG does T65.854D group to?
- T65.854D is used in the MS-DRG v44.0 logic for MS-DRG 949 (Aftercare with CC/MCC) and MS-DRG 950 (Aftercare without CC/MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.
Did T65.854D change for 2027?
- Yes. For FY2027 (effective October 1, 2026) it was added to the code set.