T65.823D — Toxic effect of harmful algae and algae toxins, assault, subsequent encounter
Is T65.823D billable?
Yes — T65.823D is billable for FY2027. T65.823D is a valid, billable ICD-10-CM code at the highest level of specificity in its branch. T65.823D may be submitted for encounters from October 1, 2026 through September 30, 2027.
T65.823D at a glance
| Code | T65.823D |
|---|---|
| Description | Toxic effect of harmful algae and algae toxins, assault, 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 T65.823D?
In T65.823D, the 7th character D means subsequent encounter. The 7th character is required for T65.823D to be a valid, complete code.
Same condition, different episode of care — switch the 7th character:
Which MS-DRGs does T65.823D group to?
T65.823D 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
How is T65.823D listed in the Alphabetic Index?
The Alphabetic Index lists these routes under T65.82, the nearest indexed parent of T65.823D. 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 T65.823D 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 T65.823D to fully describe the condition. T65.823D 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 T65.823D to fully describe the condition. T65.823D is sequenced first.
Excludes2 — not included here — inherited from Chapter 19
The conditions below are not part of T65.823D, but a patient may have both at the same time. When documentation supports it, T65.823D and the excluded code may both be reported.
How long has T65.823D existed?
T65.823D 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.