T65.824S — Toxic effect of harmful algae and algae toxins, undetermined, sequela
Is T65.824S billable?
Yes — T65.824S is billable for FY2027. T65.824S is a valid, billable ICD-10-CM code at the highest level of specificity in its branch. T65.824S may be submitted for encounters from October 1, 2026 through September 30, 2027.
T65.824S at a glance
| Code | T65.824S |
|---|---|
| Description | Toxic effect of harmful algae and algae toxins, undetermined, 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 T65.824S?
In T65.824S, the 7th character S means sequela. The 7th character is required for T65.824S to be a valid, complete code.
Same condition, different episode of care — switch the 7th character:
Which MS-DRGs does T65.824S group to?
T65.824S sits in MDC 21 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.
- 922Other Injury, Poisoning and Toxic Effect Diagnoses with MCCmedical
- 923Other Injury, Poisoning and Toxic Effect Diagnoses without MCCmedical
How is T65.824S listed in the Alphabetic Index?
The Alphabetic Index lists these routes under T65.82, the nearest indexed parent of T65.824S. Use them to find the family, then select the specific code.
- Red tide
- Poisoning › algae and toxins (acute)
Excludes1 — never code together — inherited from T51-T65
The conditions below can never be reported together with T65.824S on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
- contact with and (suspected) exposure to toxic substances (Z77.-)
Use additional code — inherited from Chapter 19
Report an additional code alongside T65.824S to fully describe the condition. T65.824S is sequenced first.
- code to identify any retained foreign body, if applicable (Z18.-)
Use additional code — inherited from T51-T65
Report an additional code alongside T65.824S to fully describe the condition. T65.824S is sequenced first.
Excludes2 — not included here — inherited from Chapter 19
The conditions below are not part of T65.824S, but a patient may have both at the same time. When documentation supports it, T65.824S and the excluded code may both be reported.
How long has T65.824S existed?
T65.824S 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.