T48.1X
Poisoning by, adverse effect of and underdosing of skeletal muscle relaxants [neuromuscular blocking agents]
T48.1X is a non-billable ICD-10-CM code header for poisoning by, adverse effect of and underdosing of skeletal muscle relaxants [neuromuscular blocking agents]. Report a more specific code from it instead. It is part of the FY2027 code set, effective October 1, 2026. The more specific codes under it are T48.1X1 Poisoning by skeletal muscle relaxants [neuromuscular blocking agents], accidental (unintentional); T48.1X2 Poisoning by skeletal muscle relaxants [neuromuscular blocking agents], intentional self-harm; T48.1X3 Poisoning by skeletal muscle relaxants [neuromuscular blocking agents], assault; T48.1X4 Poisoning by skeletal muscle relaxants [neuromuscular blocking agents], undetermined and 2 more. Its coding notes include a Code first instruction, a Use additional code instruction, 1 Excludes1 entry and 7 Excludes2 entries.
7th characters
Every code below needs one of these (defined at T48).
The appropriate 7th character is to be added to each code from category T48
- Ainitial encounter
- Dsubsequent encounter
- Ssequela
Guidelines tips
From the FY2027 Official Guidelines. ICD10Ref adds no rules of its own.
The 7th character depends on whether the patient is in active treatment, not on who sees the patient. An aftercare Z code is not used for injury aftercare.
T36-T65 codes already include the substance and the intent, so no additional external cause code is required. Do not code directly from the Table of Drugs and Chemicals.
Code first
If the underlying condition listed here is present and known, sequence it first.
Also from chapter/block level (7 notes)
Use additional code
Add the listed code as a secondary code, if known.
Also from chapter/block level (5 notes)
- code to identify any retained foreign body, if applicable (Z18.-)
Excludes1
Not coded here. The listed conditions generally should not be reported together.
Excludes2
Not included here. Both codes may be reported if the patient has both conditions.
Also from chapter/block level (7 notes)
- birth trauma (P10-P15)
- obstetric trauma (O70-O71)
Includes
Further defines or gives examples of the content of the category.
Also from chapter/block level (4 notes)
- adverse effect of correct substance properly administered
- poisoning by overdose of substance
- poisoning by wrong substance given or taken in error
- underdosing by (inadvertently) (deliberately) taking less substance than prescribed or instructed
Notes
Also from chapter/block level (3 notes)
- The drug giving rise to the adverse effect should be identified by use of codes from categories T36-T50 with fifth or sixth character 5.
- Use secondary code(s) from Chapter 20, External causes of morbidity, to indicate cause of injury. Codes within the T section that include the external cause do not require an additional external cause code
- The chapter uses the S-section for coding different types of injuries related to single body regions and the T-section to cover injuries to unspecified body regions as well as poisoning and certain other consequences of external causes.
More specific codes under T48.1X 6
- T48.1X1Poisoning by skeletal muscle relaxants [neuromuscular blocking agents], accidental (unintentional)7th char needed
- T48.1X2Poisoning by skeletal muscle relaxants [neuromuscular blocking agents], intentional self-harm7th char needed
- T48.1X3Poisoning by skeletal muscle relaxants [neuromuscular blocking agents], assault7th char needed
- T48.1X4Poisoning by skeletal muscle relaxants [neuromuscular blocking agents], undetermined7th char needed
- T48.1X5Adverse effect of skeletal muscle relaxants [neuromuscular blocking agents]7th char needed
- T48.1X6Underdosing of skeletal muscle relaxants [neuromuscular blocking agents]7th char needed