T39.4X6S — Underdosing of antirheumatics, not elsewhere classified, sequela
Is T39.4X6S billable?
Yes, but T39.4X6S is an unspecified code. T39.4X6S is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, T39.4X6S 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 T39.4X6S — the more specific alternatives are listed below.
More specific alternatives
- T39.011SPoisoning by aspirin, accidental (unintentional), sequela
- T39.1X1SPoisoning by 4-Aminophenol derivatives, accidental (unintentional), sequela
- T39.2X1SPoisoning by pyrazolone derivatives, accidental (unintentional), sequela
- T39.311SPoisoning by propionic acid derivatives, accidental (unintentional), sequela
T39.4X6S at a glance
| Code | T39.4X6S |
|---|---|
| Description | Underdosing of antirheumatics, not elsewhere classified, 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 T39.4X6S?
In T39.4X6S, the 7th character S means sequela. The 7th character is required for T39.4X6S to be a valid, complete code.
Same condition, different episode of care — switch the 7th character:
What Medicare edits apply to T39.4X6S?
The Medicare Code Editor screens inpatient claims before they are grouped. These edits name T39.4X6S 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 T39.4X6S group to?
T39.4X6S 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 T39.4X6S 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-)
Excludes1 — never code together — inherited from T39.4
The conditions below can never be reported together with T39.4X6S on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
Code first — inherited from T36-T50
The underlying condition below must be sequenced before T39.4X6S. T39.4X6S describes a manifestation and cannot be the principal or first-listed diagnosis.
Use additional code — inherited from Chapter 19
Report an additional code alongside T39.4X6S to fully describe the condition. T39.4X6S 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 T39.4X6S to fully describe the condition. T39.4X6S is sequenced first.
Excludes2 — not included here — inherited from Chapter 19
The conditions below are not part of T39.4X6S, but a patient may have both at the same time. When documentation supports it, T39.4X6S and the excluded code may both be reported.
Excludes2 — not included here — inherited from T36-T50
The conditions below are not part of T39.4X6S, but a patient may have both at the same time. When documentation supports it, T39.4X6S and the excluded code may both be reported.
How long has T39.4X6S existed?
T39.4X6S 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.