T40.606S — Underdosing of unspecified narcotics, sequela
Is T40.606S billable?
Yes, but T40.606S is an unspecified code. T40.606S is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, T40.606S 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 T40.606S — the more specific alternatives are listed below.
More specific alternatives
- T40.0X1SPoisoning by opium, accidental (unintentional), sequela
- T40.1X1SPoisoning by heroin, accidental (unintentional), sequela
- T40.2X1SPoisoning by other opioids, accidental (unintentional), sequela
- T40.3X1SPoisoning by methadone, accidental (unintentional), sequela
- T40.411SPoisoning by fentanyl or fentanyl analogs, accidental (unintentional), sequela
- T40.5X1SPoisoning by cocaine, accidental (unintentional), sequela
- T40.711SPoisoning by cannabis, accidental (unintentional), sequela
- T40.8X1SPoisoning by lysergide [LSD], accidental (unintentional), sequela
T40.606S at a glance
| Code | T40.606S |
|---|---|
| Description | Underdosing of unspecified narcotics, sequela |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
| 7th character "S" | sequela |
What does the 7th character "S" mean in T40.606S?
In T40.606S, the 7th character S means sequela. The 7th character is required for T40.606S to be a valid, complete code.
Same condition, different episode of care — switch the 7th character:
What Medicare edits apply to T40.606S?
The Medicare Code Editor screens inpatient claims before they are grouped. These edits name T40.606S 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 T40.606S group to?
T40.606S sits in MDC 23 and helps define the logic of 2 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 949Aftercare with CC/MCCmedical
- 950Aftercare without CC/MCCmedical
Excludes1 — never code together — inherited from T36-T50
The conditions below can never be reported together with T40.606S 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 T40.606S. T40.606S describes a manifestation and cannot be the principal or first-listed diagnosis.
Use additional code — inherited from Chapter 19
Report an additional code alongside T40.606S to fully describe the condition. T40.606S 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 T40.606S to fully describe the condition. T40.606S is sequenced first.
Excludes2 — not included here — inherited from Chapter 19
The conditions below are not part of T40.606S, but a patient may have both at the same time. When documentation supports it, T40.606S and the excluded code may both be reported.
Excludes2 — not included here — inherited from T36-T50
The conditions below are not part of T40.606S, but a patient may have both at the same time. When documentation supports it, T40.606S and the excluded code may both be reported.
Excludes2 — not included here — inherited from T40
The conditions below are not part of T40.606S, but a patient may have both at the same time. When documentation supports it, T40.606S 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 T40.606S existed?
T40.606S has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.