T42.4X6D — Underdosing of benzodiazepines, subsequent encounter
Is T42.4X6D billable?
Yes — T42.4X6D is billable for FY2027. T42.4X6D is a valid, billable ICD-10-CM code at the highest level of specificity in its branch. T42.4X6D may be submitted for encounters from October 1, 2026 through September 30, 2027.
T42.4X6D at a glance
| Code | T42.4X6D |
|---|---|
| Description | Underdosing of benzodiazepines, subsequent encounter |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
| 7th character "D" | subsequent encounter |
What does the 7th character "D" mean in T42.4X6D?
In T42.4X6D, the 7th character D means subsequent encounter. The 7th character is required for T42.4X6D to be a valid, complete code.
Same condition, different episode of care — switch the 7th character:
What Medicare edits apply to T42.4X6D?
The Medicare Code Editor screens inpatient claims before they are grouped. These edits name T42.4X6D 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 T42.4X6D group to?
T42.4X6D 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 T42.4X6D 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 T42.4X6D. T42.4X6D describes a manifestation and cannot be the principal or first-listed diagnosis.
Use additional code — inherited from Chapter 19
Report an additional code alongside T42.4X6D to fully describe the condition. T42.4X6D 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 T42.4X6D to fully describe the condition. T42.4X6D is sequenced first.
Excludes2 — not included here — inherited from Chapter 19
The conditions below are not part of T42.4X6D, but a patient may have both at the same time. When documentation supports it, T42.4X6D and the excluded code may both be reported.
Excludes2 — not included here — inherited from T36-T50
The conditions below are not part of T42.4X6D, but a patient may have both at the same time. When documentation supports it, T42.4X6D and the excluded code may both be reported.
Excludes2 — not included here — inherited from T42
The conditions below are not part of T42.4X6D, but a patient may have both at the same time. When documentation supports it, T42.4X6D 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 T42.4X6D existed?
T42.4X6D 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.