ICDcodes.org
FY2027

T45.1X5AAdverse effect of antineoplastic and immunosuppressive drugs, initial encounter

Billable

Is T45.1X5A billable?

Yes — T45.1X5A is billable for FY2027. T45.1X5A is a valid, billable ICD-10-CM code at the highest level of specificity in its branch. T45.1X5A may be submitted for encounters from October 1, 2026 through September 30, 2027.

T45.1X5A at a glance

CodeT45.1X5A
DescriptionAdverse effect of antineoplastic and immunosuppressive drugs, 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 T45.1X5A?

In T45.1X5A, the 7th character A means initial encounter. The 7th character is required for T45.1X5A to be a valid, complete code.

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

What Medicare edits apply to T45.1X5A?

The Medicare Code Editor screens inpatient claims before they are grouped. These edits name T45.1X5A 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 T45.1X5A group to?

T45.1X5A 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

Excludes1 — never code together — inherited from T36-T50

The conditions below can never be reported together with T45.1X5A 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 T45.1

The conditions below can never be reported together with T45.1X5A on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.

  • poisoning by, adverse effect of and underdosing of immune checkpoint inhibitors and immunostimulant drugs (T45.A)
  • poisoning by, adverse effect of and underdosing of tamoxifen (T38.6)

Code first — inherited from T36-T50

The underlying condition below must be sequenced before T45.1X5A. T45.1X5A 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 T45.1X5A to fully describe the condition. T45.1X5A 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 T45.1X5A to fully describe the condition. T45.1X5A 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 T45.1X5A, but a patient may have both at the same time. When documentation supports it, T45.1X5A 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 T45.1X5A, but a patient may have both at the same time. When documentation supports it, T45.1X5A 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)

How long has T45.1X5A existed?

T45.1X5A 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.