ICD code T43.214S – Sequela of SNRI poisoning

Key takeaways

T43.214S reports the sequela (late effects) of SNRI poisoning, such as venlafaxine or duloxetine, where the record states intent could not be determined.

Sequela of SSRI poisoning is coded from T43.22- instead, so confirm the drug class before you assign a T43.21- code.

The resulting sequela condition is coded first, and T43.214S follows as an additional code.

Common denial causes include a wrong 7th character (A or D instead of S), a wrong intent character, and a missing lead sequela diagnosis.

Pabau, the practice management platform we build, keeps clinical notes and billing together and submits claims electronically through Claim.MD.

ICD-10 code T43.214S: Definition and code details

ICD-10 code T43.214S is a billable diagnosis code for poisoning by selective serotonin and norepinephrine reuptake inhibitors, undetermined, sequela. It reports a late effect of a prior SNRI poisoning where the record states the intent could not be determined. The ‘S’ 7th character marks a visit for that late effect, after the poisoning itself has resolved.

The code sits in Chapter 19 of the ICD-10-CM code set (Injury, poisoning and certain other consequences of external causes, S00-T88). Its hierarchy runs from T43 (psychotropic drugs) to T43.2 (other and unspecified antidepressants) and then T43.21 (SNRIs). T43.214 adds undetermined intent and needs a 7th character, and T43.214S is the sequela encounter. SSRIs have their own subcategory, T43.22.

Code details at a glance

Verify the code remains active each October 1, when annual ICD-10-CM updates take effect. Use the CDC/NCHS ICD-10-CM web tool to confirm validity against the current fiscal year release.

Understanding the 7th character ‘S’ for T43.214S

The 7th character ‘S’ means the patient is presenting with a condition that is a direct consequence of a prior, now-resolved poisoning episode. The original poisoning encounter is over, and ‘S’ captures the lasting harm the drug caused.

The ICD-10-CM Official Guidelines for Coding and Reporting (OGCR) cover sequela in Sections I.B.10 and I.C.19.a. A sequela is a residual effect that remains after the acute phase ends. The sequela condition is coded first, and T43.214S follows it. The ‘S’ goes on the T code only, never on the condition code.

T43.214A, T43.214D, and T43.214S compared

A common documentation error is reporting T43.214D after the acute episode has clinically resolved. Once the visit treats a residual condition and not the poisoning itself, the 7th character changes to ‘S’.

What T43.214S covers and what it excludes

T43.214S applies only to sequela of poisoning by serotonin and norepinephrine reuptake inhibitors (SNRIs). Drugs in scope include venlafaxine, duloxetine, desvenlafaxine, and levomilnacipran. Selective serotonin reuptake inhibitors (SSRIs) such as fluoxetine, sertraline, paroxetine, citalopram, escitalopram, and fluvoxamine are classified under T43.22-, with T43.224S as their undetermined sequela code. Confirm each drug’s class in the ICD-10-CM Table of Drugs and Chemicals.

Includes and excludes at a glance

• Includes: Sequela of poisoning by an SNRI where the record states the intent cannot be determined
• Includes: Any residual condition documented as caused by that prior poisoning (neurological, psychiatric, or other)
• Excludes: Sequela of SSRI poisoning, such as sertraline or fluoxetine (use T43.22-, or T43.224S for undetermined intent)
• Excludes: Sequela of SNRI poisoning with known intent (use T43.211S for accidental, T43.212S for intentional self-harm, or T43.213S for assault)
• Excludes: Unknown or unspecified intent, which the OGCR codes as accidental (use T43.211S)
• Excludes: Adverse effect of a correctly prescribed and properly administered SNRI (use T43.215-)
• Excludes: Underdosing of an SNRI (use T43.216-)
• Excludes: Active or ongoing SNRI poisoning encounter (use T43.214A or T43.214D)
• Excludes: Sequela of poisoning by other antidepressant classes, such as tricyclics (T43.014S), MAOIs (T43.1X4S), or unspecified antidepressants (T43.204S)

Poisoning vs adverse effect vs underdosing in ICD-10-CM

These three categories describe different clinical scenarios, and each has its own 6th character. Mixing them up changes the claim and can trigger a payer audit. The Table of Drugs and Chemicals uses the same split for every drug, which makes it one of the medical billing fundamentals worth learning early.

Intent is part of the poisoning code itself. The 6th character records it: 1 for accidental, 2 for intentional self-harm, 3 for assault, and 4 for undetermined. T43.214S therefore covers undetermined intent only, carried forward from the original encounter.

If the original poisoning was accidental, self-harm, or assault, use T43.211S, T43.212S, or T43.213S instead. The OGCR codes unknown or unspecified intent as accidental. Reserve undetermined intent for records that state the intent cannot be determined.

Clinical scenarios where T43.214S applies

T43.214S is correct when a patient’s current condition is documented as a direct consequence of a resolved SNRI poisoning. The original record must also state that intent could not be determined. In outpatient psychiatry, this code usually appears at follow-up visits weeks to months after the original event.

Common sequela presentations include persistent cognitive impairment, mood disturbances, or neurological effects such as tremor or coordination difficulties traceable to the overdose. The OGCR requires documentation linking the current condition to the original poisoning. Without that link in the record, the code cannot be supported.

Clinical vignette: Correct T43.214S application

Original encounter (6 months prior): Patient admitted after a venlafaxine overdose. The patient could not recall the event, and the treating team documented that intent could not be determined. Coded T43.214A (initial encounter, undetermined intent). Serotonin syndrome was treated and resolved during the inpatient stay.

Current visit: Patient presents to outpatient psychiatry with documented persistent short-term memory difficulties and concentration deficits. Treating physician documents in the note: “Cognitive impairment consistent with sequela of prior venlafaxine overdose admitted [date].”

Correct coding: Sequence the sequela condition first, using a code from category F06 (mental disorders due to known physiological condition) that matches the documented deficit. Then add T43.214S as the additional causal code.

Correct code sequencing for T43.214S

Sequencing for T43.214S follows the OGCR sequela rules. The condition resulting from the poisoning is coded first, and T43.214S is added to identify the causal drug and episode. T43.214S is never the principal or first-listed diagnosis on its own. Three checks decide whether the visit reaches it at all.

1. Identify the sequela condition: Document the specific condition the patient currently has as a result of the poisoning (e.g., cognitive impairment, mood disorder, neurological deficit). This becomes the principal or first-listed diagnosis.
2. Assign the sequela condition code: Select the ICD-10-CM code for the documented condition. Psychiatric sequela usually take an F code, and neurological effects a G code.
3. Add T43.214S as an additional code: Sequence T43.214S after the sequela condition code. It identifies the cause, a resolved SNRI poisoning of undetermined intent.
4. Check the drug class and intent: Confirm the drug was an SNRI and the original record states intent could not be determined. Otherwise, use T43.224S for an SSRI or T43.211S to T43.213S for known intent. No separate external cause code is needed for intent, because the T code already carries it.
5. Do not report the original poisoning code: T43.214A or T43.214D from the original encounter are not re-reported on the sequela visit. T43.214S replaces them for this encounter.

Commonly confused T43 codes

The T43.21- subcategory holds a code for each intent and encounter type of SNRI poisoning, plus adverse effect and underdosing. SSRI codes sit next door in T43.22-, which makes the two easy to mix up.

Documentation requirements for billing T43.214S

Payers expect the medical record to support T43.214S before they pay the claim. A missing element from the list below is a common reason these claims are denied. Claims management software keeps the note and the claim in one place, so coders can check the record before submission.

• Prior poisoning episode documented: The record must document the original SNRI poisoning. Include the encounter date, drugs involved, documented intent, and clinical management.
• Sequela condition explicitly linked: The treating clinician must document that the current condition is a direct consequence of the prior poisoning. An assumed link is not enough, so the note must state the clinical connection.
• Temporal plausibility: The timeline between the original poisoning and the current sequela presentation must be clinically reasonable and documented.
• Sequela condition coded first: The claim must reflect the OGCR sequencing rule, with the sequela condition as primary and T43.214S as additional.
• Physician attestation: The treating provider must sign and date documentation supporting the sequela diagnosis before claim submission.

CMS guidelines require that diagnosis codes be supported by the provider’s documentation in the medical record. For sequela codes, auditors may ask for the prior encounter record itself, not only a reference to it.

Why T43.214S claims get denied and how to prevent it

T43.214S claims are often denied because the sequencing rule runs against the habit of listing the main diagnosis first. Each reason below traces back to one step in coding or documentation, and that step is where denial management workflows should catch it. The table below maps each common denial reason to a prevention step.

For practices with high volumes of psychiatric and toxicology claims, submitting a clean claim means catching these issues before they reach the payer. A pre-submission check that flags T43.214S with no sequela condition code above it removes a common cause of denial in this category.

How Pabau supports clean claims for T43.214S

Coding T43.214S correctly depends on the record. The coder needs the original poisoning, its documented intent, and the stated link to today’s condition. When notes and claims live in separate systems, those details get lost between the visit and the claim.

Pabau’s practice software keeps clinical notes and billing in one patient record. Claims go out electronically through the Claim.MD integration, which every subscription includes. Your coders can review the sequela documentation and the code order in one place before the claim leaves the practice.

Submit SNRI sequela claims from one record

Pabau keeps clinical notes and billing together and sends claims electronically through Claim.MD, included in every subscription. Your team can check sequela documentation and code order before each claim goes out.

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Conclusion

T43.214S is narrow by design. It fits one drug class (SNRIs), one intent (undetermined), and one encounter type (sequela). A case that misses any of the three needs a different code, such as T43.224S for an SSRI or T43.211S for unspecified intent.

Before you assign it, confirm the drug class and read how the original record describes intent. Then check that today’s note states the link to the prior poisoning and that the sequela condition is coded first. With those steps in place, the claim holds up when a payer asks for the records.

Pabau supports the wider revenue cycle management workflow by keeping notes and claims together. Book a demo to see how it helps your team submit accurate psychiatric and toxicology claims.

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