ICDcodes.org
FY2027

T43.205AAdverse effect of unspecified antidepressants, initial encounter

BillableUnspecified

Is T43.205A billable?

Yes, but T43.205A is an unspecified code. T43.205A is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, T43.205A 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 T43.205A.

T43.205A at a glance

CodeT43.205A
DescriptionAdverse effect of unspecified antidepressants, initial encounter
BillableYes
Code setICD-10-CM FY2027
Valid for encountersOctober 1, 2026 – September 30, 2027
7th character "A"initial encounter

What does the 7th character "A" mean in T43.205A?

In T43.205A, the 7th character A means initial encounter. The 7th character is required for T43.205A to be a valid, complete code.

Same condition, different episode of care — switch the 7th character:

What Medicare edits apply to T43.205A?

The Medicare Code Editor screens inpatient claims before they are grouped. These edits name T43.205A directly.

Cannot be a principal diagnosis — MCE edit 9

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 T43.205A group to?

T43.205A sits in MDC 15 and helps define the logic of 1 MS-DRG (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.

  • 791Prematurity with Major Problemsmedical

How is T43.205A listed in the Alphabetic Index?

The Alphabetic Index lists these routes under T43.205, the nearest indexed parent of T43.205A. Use them to find the family, then select the specific code.

  • Syndromeantidepressant discontinuation

Inclusion terms

Alternative wording in documentation that is classified to T43.205A.

  • Antidepressant discontinuation syndrome

Excludes1 — never code together — inherited from T36-T50

The conditions below can never be reported together with T43.205A 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 T43.205A. T43.205A describes a manifestation and cannot be the principal or first-listed diagnosis.

  • , for adverse effects, the nature of the adverse effect, such as:
  • adverse effect NOS (T88.7)
  • aspirin gastritis (K29.-)
  • blood disorders (D56-D76)
  • contact dermatitis (L23-L25)
  • dermatitis due to substances taken internally (L27.-)
  • nephropathy (N14.0-N14.2)

Use additional code — inherited from Chapter 19

Report an additional code alongside T43.205A to fully describe the condition. T43.205A 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 T43.205A to fully describe the condition. T43.205A is sequenced first.

  • code(s) to specify:
  • manifestations of poisoning
  • underdosing or failure in dosage during medical and surgical care (Y63.6, Y63.8-Y63.9)
  • underdosing of medication regimen (Z91.12-, Z91.13-)

Excludes2 — not included here — inherited from Chapter 19

The conditions below are not part of T43.205A, but a patient may have both at the same time. When documentation supports it, T43.205A and the excluded code may both be reported.

  • birth trauma (P10-P15)
  • obstetric trauma (O70-O71)

Excludes2 — not included here — inherited from T36-T50

The conditions below are not part of T43.205A, but a patient may have both at the same time. When documentation supports it, T43.205A and the excluded code may both be reported.

  • abuse and dependence of psychoactive substances (F10-F19)
  • abuse of non-dependence-producing substances (F55.-)
  • immunodeficiency due to drugs (D84.821)
  • drug reaction and poisoning affecting newborn (P00-P96)
  • pathological drug intoxication (inebriation) (F10-F19)

Excludes2 — not included here — inherited from T43

The conditions below are not part of T43.205A, but a patient may have both at the same time. When documentation supports it, T43.205A and the excluded code may both be reported.

  • appetite depressants (T50.5-)
  • barbiturates (T42.3-)
  • benzodiazepines (T42.4-)
  • drug dependence and related mental and behavioral disorders due to psychoactive substance use (F10.- -F19.-)
  • methaqualone (T42.6-)
  • psychodysleptics [hallucinogens] (T40.7-T40.9-)

How long has T43.205A existed?

T43.205A 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.