T42.73XA
Poisoning by unspecified antiepileptic and sedative-hypnotic drugs, assault, initial encounter
This code does not map to a risk-adjusting HCC in the loaded models.
Coding notes
Excludes 1 never coded together · Excludes 2 may co-exist
drug dependence and related mental and behavioral disorders due to psychoactive substance use (F10.--F19.-)
The appropriate 7th character is to be added to each code from category T42
| Character | Meaning |
|---|---|
| A | initial encounter |
| D | subsequent encounter |
| S | sequela |
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
toxic reaction to local anesthesia in pregnancy (O29.3-)
abuse and dependence of psychoactive substances (F10-F19) abuse of non-dependence-producing substances (F55.-) immunodeficiency due to drugs (D84.821) drug reaction and poisoning affecting newborn (P00-P96) pathological drug intoxication (inebriation) (F10-F19)
code(s) to specify: manifestations of poisoning underdosing or failure in dosage during medical and surgical care (Y63.6, Y63.8-Y63.9) underdosing of medication regimen (Z91.12-, Z91.13-)
, for adverse effects, the nature of the adverse effect, such as: adverse effect NOS (T88.7) aspirin gastritis (K29.-) blood disorders (D56-D76) contact dermatitis (L23-L25) dermatitis due to substances taken internally (L27.-) nephropathy (N14.0-N14.2)
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.
code to identify any retained foreign body, if applicable (Z18.-)
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. (T07-T88) Injury, poisoning and certain other consequences of external causes (T07-T88) (T20-T32) Burns and corrosions (T20-T32) Includes: burns (thermal) from electrical heating appliances burns (thermal) from electricity burns (thermal) from flame burns (thermal) from friction burns (thermal) from hot air and hot gases burns (thermal) from hot objects burns (thermal) from lightning burns (thermal) from radiation chemical burn [corrosion] (external) (internal) scalds Excludes2: erythema [dermatitis] ab igne (L59.0) radiation-related disorders of the skin and subcutaneous tissue (L55-L59) sunburn (L55.-)
Official Guidelines for T42.73XA
FY 2026 ›Subsections
- I.C.19.aApplication of 7th Characters in Chapter 19
- I.C.19.bCoding of Injuries
- I.C.19.cCoding of Traumatic Fractures
- I.C.19.dCoding of Burns and Corrosions
- I.C.19.eAdverse Effects, Poisoning, Underdosing and Toxic Effects
- I.C.19.fAdult and child abuse, neglect and other maltreatment
- I.C.19.gComplications of care
Sections that reference T42.73XA
- I.A.4Placeholder characterConventions & general rules
… An example of this is at the poisoning, adverse effect and underdosing codes, categories T36-T50. Where a placeholder exists, the X must be used in order for the code to be considered a valid code. …
- I.C.19.eAdverse Effects, Poisoning, Underdosing and Toxic Effects
Codes in categories T36-T65 are combination codes that include the substance that was taken as well as the intent. …
- I.C.19.e.5)(a)Adverse Effect
… appropriate code for the nature of the adverse effect followed by the appropriate code for the adverse effect of the drug (T36-T50). …
- I.C.19.e.5)(b)Poisoning
… wrong substance given or taken in error, wrong route of administration), first assign the appropriate code from categories T36-T50. The poisoning codes have an associated intent as their 5th or 6th character (accidental, intentional self-harm, assault and …
- I.C.19.e.5)(c)Underdosing
… For underdosing, assign the code from categories T36-T50 (fifth or sixth character “6”). …
Sections whose FY 2026 text names T42.73XA, its T42 category, or a range containing it — the chapter guidance above is the authoritative source.
In the Table of Drugs and Chemicals
12 substances map to T42.73XA. If a chart lists more than one of them, they collapse onto this single code.
One of them: Anticonvulsant, column Poisoning Assault.
Anticonvulsant in every column
This row belongs to Anticonvulsant. Other substances sharing T42.73XA may differ in the remaining columns — check the one in your documentation.
- Poisoning Accidental (unintentional)T42.710.000maps to no HCC category
- Poisoning Intentional self-harmT42.720.299HCC155maps to HCC155age >= 2
- Poisoning AssaultT42.730.000maps to no HCC category
- Poisoning UndeterminedT42.740.000maps to no HCC category
- Adverse effectT42.750.000maps to no HCC category
- UnderdosingT42.760.000maps to no HCC category
Billable forms: T42.73XA · T42.73XD · T42.73XS — under CMS-HCC V28 only the A form risk-adjusts.
The column is chosen by the documentation, not by the coder. Intent follows the documented circumstance; adverse effect requires that the drug was correctly prescribed and properly administered (Guideline I.C.19.e). Coefficients are Community, Non-Dual, Aged under CMS-HCC V28 PY2027. How these figures were derived.