T40.906A — Underdosing of unspecified psychodysleptics [hallucinogens], initial encounter
Is T40.906A billable?
Yes, but T40.906A is an unspecified code. T40.906A is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, T40.906A is an unspecified or catch-all code. Payers apply additional scrutiny to unspecified codes and many deny them when the medical record supports a more specific option, so check the documentation before selecting T40.906A — the more specific alternatives are listed below.
More specific alternatives
- T40.0X1APoisoning by opium, accidental (unintentional), initial encounter
- T40.1X1APoisoning by heroin, accidental (unintentional), initial encounter
- T40.2X1APoisoning by other opioids, accidental (unintentional), initial encounter
- T40.3X1APoisoning by methadone, accidental (unintentional), initial encounter
- T40.411APoisoning by fentanyl or fentanyl analogs, accidental (unintentional), initial encounter
- T40.5X1APoisoning by cocaine, accidental (unintentional), initial encounter
- T40.711APoisoning by cannabis, accidental (unintentional), initial encounter
- T40.8X1APoisoning by lysergide [LSD], accidental (unintentional), initial encounter
T40.906A at a glance
| Code | T40.906A |
|---|---|
| Description | Underdosing of unspecified psychodysleptics [hallucinogens], initial encounter |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
| 7th character "A" | initial encounter |
What does the 7th character "A" mean in T40.906A?
In T40.906A, the 7th character A means initial encounter. The 7th character is required for T40.906A to be a valid, complete code.
Same condition, different episode of care — switch the 7th character:
What Medicare edits apply to T40.906A?
The Medicare Code Editor screens inpatient claims before they are grouped. These edits name T40.906A directly.
CMS will reject this code as the principal diagnosis on an inpatient claim. It describes something other than the condition chiefly responsible for the admission.
Which MS-DRGs does T40.906A group to?
T40.906A sits in MDC 23 and helps define the logic of 1 MS-DRG (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 951Other Factors Influencing Health Statusmedical
Excludes1 — never code together — inherited from T36-T50
The conditions below can never be reported together with T40.906A on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
- toxic reaction to local anesthesia in pregnancy (O29.3-)
Code first — inherited from T36-T50
The underlying condition below must be sequenced before T40.906A. T40.906A describes a manifestation and cannot be the principal or first-listed diagnosis.
Use additional code — inherited from Chapter 19
Report an additional code alongside T40.906A to fully describe the condition. T40.906A is sequenced first.
- code to identify any retained foreign body, if applicable (Z18.-)
Use additional code — inherited from T36-T50
Report an additional code alongside T40.906A to fully describe the condition. T40.906A is sequenced first.
Excludes2 — not included here — inherited from Chapter 19
The conditions below are not part of T40.906A, but a patient may have both at the same time. When documentation supports it, T40.906A and the excluded code may both be reported.
Excludes2 — not included here — inherited from T36-T50
The conditions below are not part of T40.906A, but a patient may have both at the same time. When documentation supports it, T40.906A and the excluded code may both be reported.
Excludes2 — not included here — inherited from T40
The conditions below are not part of T40.906A, but a patient may have both at the same time. When documentation supports it, T40.906A and the excluded code may both be reported.
- drug dependence and related mental and behavioral disorders due to psychoactive substance use (F10.-F19.-)
How long has T40.906A existed?
T40.906A has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
- FY2021Underdosing of unspecified psychodysleptics, initial encounterUnderdosing of unspecified psychodysleptics [hallucinogens], initial encounter
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.