ICDcodes.org
FY2027

I23.1 — Atrial septal defect as current complication following acute myocardial infarction

BillableCC

Is I23.1 billable?

Yes — I23.1 is billable for FY2027. I23.1 is a valid, billable ICD-10-CM code at the highest level of specificity in its branch. I23.1 may be submitted for encounters from October 1, 2026 through September 30, 2027.

I23.1 at a glance

CodeI23.1
DescriptionAtrial septal defect as current complication following acute myocardial infarction
BillableYes
Code setICD-10-CM FY2027
Valid for encountersOctober 1, 2026 – September 30, 2027

Which MS-DRGs does I23.1 group to?

I23.1 sits in MDC 05 and helps define the logic of 3 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.

  • 314Other Circulatory System Diagnoses with MCCmedical
  • 315Other Circulatory System Diagnoses with CCmedical
  • 316Other Circulatory System Diagnoses without CC/MCCmedical

As a secondary diagnosis, I23.1 is a complication or comorbidity (CC), which can move a stay into a higher-paying DRG.

How is I23.1 listed in the Alphabetic Index?

These are the routes through the Alphabetic Index that lead to I23.1. They show the wording a clinician may have documented, which often differs from the Tabular description.

  • Defect, defective › atrial septal › following acute myocardial infarction
  • Defect, defective › septalNOS › atrial › following acute myocardial infarction
  • Complication › following › acute myocardial infarction NEC › atrial › septal defect (s) (from) (of)
  • Complication › following › acute myocardial infarction NEC › defect › septal › atrial (s) (from) (of)

Excludes1 — never code together

The conditions below can never be reported together with I23.1 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.

  • acquired atrial septal defect not specified as current complication following acute myocardial infarction (I51.0)

Excludes2 — not included here — inherited from Chapter 9

The conditions below are not part of I23.1, but a patient may have both at the same time. When documentation supports it, I23.1 and the excluded code may both be reported.

  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
  • systemic connective tissue disorders (M30-M36)
  • transient cerebral ischemic attacks and related syndromes (G45.-)

Code also — inherited from I20-I25

Two codes may be needed to describe the condition fully. Whether I23.1 is sequenced first depends on the reason for the encounter.

  • the presence of hypertension (I10-I1A)

How long has I23.1 existed?

I23.1 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.

Which codes are confused with I23.1?

ICD-10-CM declares these codes mutually exclusive with I23.1 — exactly one of each pair can be correct for a given encounter.

Which conditions are coded to I23.1?

What other codes are in the I23 family? (8)