T43.4X6S — Underdosing of butyrophenone and thiothixene neuroleptics, sequela
Is T43.4X6S billable?
Yes — T43.4X6S is billable for FY2027. T43.4X6S is a valid, billable ICD-10-CM code at the highest level of specificity in its branch. T43.4X6S may be submitted for encounters from October 1, 2026 through September 30, 2027.
T43.4X6S at a glance
| Code | T43.4X6S |
|---|---|
| Description | Underdosing of butyrophenone and thiothixene neuroleptics, 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 T43.4X6S?
In T43.4X6S, the 7th character S means sequela. The 7th character is required for T43.4X6S to be a valid, complete code.
Same condition, different episode of care — switch the 7th character:
What Medicare edits apply to T43.4X6S?
The Medicare Code Editor screens inpatient claims before they are grouped. These edits name T43.4X6S 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 T43.4X6S group to?
T43.4X6S 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 T43.4X6S 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 T43.4X6S. T43.4X6S describes a manifestation and cannot be the principal or first-listed diagnosis.
Use additional code — inherited from Chapter 19
Report an additional code alongside T43.4X6S to fully describe the condition. T43.4X6S 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 T43.4X6S to fully describe the condition. T43.4X6S is sequenced first.
Excludes2 — not included here — inherited from Chapter 19
The conditions below are not part of T43.4X6S, but a patient may have both at the same time. When documentation supports it, T43.4X6S and the excluded code may both be reported.
Excludes2 — not included here — inherited from T36-T50
The conditions below are not part of T43.4X6S, but a patient may have both at the same time. When documentation supports it, T43.4X6S and the excluded code may both be reported.
Excludes2 — not included here — inherited from T43
The conditions below are not part of T43.4X6S, but a patient may have both at the same time. When documentation supports it, T43.4X6S and the excluded code may both be reported.
How long has T43.4X6S existed?
T43.4X6S 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.