T53.5X1AToxic effect of chlorofluorocarbons, accidental (unintentional), initial encounter

T53.5X1A is the ICD-10-CM diagnosis code for toxic effect of chlorofluorocarbons, accidental (unintentional), initial encounter. It belongs to category T53 (toxic effect of halogen derivatives of aliphatic and aromatic hydrocarbons), 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 "A" means initial encounter: use it while the patient is receiving active treatment for the condition.

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 917 (Poisoning and Toxic Effects of Drugs with MCC, relative weight 1.57) and DRG 918 (Poisoning and Toxic Effects of Drugs without MCC, relative weight 0.872), in MDC 21 (Injuries, Poisonings and Toxic Effects of Drugs), 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 has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 987.4 (toxic effect of freon) and E869.2 (accidental poisoning by freon).