ICDcodes.org
FY2027

I25.9 — Chronic ischemic heart disease, unspecified

BillableUnspecified

Is I25.9 billable?

Yes, but I25.9 is an unspecified code. I25.9 is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, I25.9 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 I25.9 — the more specific alternatives are listed below.

I25.9 at a glance

CodeI25.9
DescriptionChronic ischemic heart disease, unspecified
BillableYes
Code setICD-10-CM FY2027
Valid for encountersOctober 1, 2026 – September 30, 2027

Which MS-DRGs does I25.9 group to?

I25.9 sits in MDC 05 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.

  • 302Atherosclerosis with MCCmedical
  • 303Atherosclerosis without MCCmedical

How is I25.9 listed in the Alphabetic Index?

These are the routes through the Alphabetic Index that lead to I25.9. They show the wording a clinician may have documented, which often differs from the Tabular description.

  • Deformity › coronary artery
  • Ischemia, ischemic › heart
  • Ischemia, ischemic › myocardium, myocardial
  • Ischemia, ischemic › supply
  • Deformity › arteryNOS › coronary
  • Disease, diseased › heart › ischemic

Inclusion terms

Alternative wording in documentation that is classified to I25.9.

  • Ischemic heart disease (chronic) NOS

Use additional code — inherited from I25

Report an additional code alongside I25.9 to fully describe the condition. I25.9 is sequenced first.

  • code to identify:
  • chronic total occlusion of coronary artery (I25.82)
  • exposure to environmental tobacco smoke (Z77.22)
  • history of tobacco dependence (Z87.891)
  • occupational exposure to environmental tobacco smoke (Z57.31)
  • tobacco dependence (F17.-)
  • tobacco use (Z72.0)

Excludes2 — not included here — inherited from Chapter 9

The conditions below are not part of I25.9, but a patient may have both at the same time. When documentation supports it, I25.9 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.-)

Excludes2 — not included here — inherited from I25

The conditions below are not part of I25.9, but a patient may have both at the same time. When documentation supports it, I25.9 and the excluded code may both be reported.

  • non-ischemic myocardial injury (I5A)

Code also — inherited from I20-I25

Two codes may be needed to describe the condition fully. Whether I25.9 is sequenced first depends on the reason for the encounter.

  • the presence of hypertension (I10-I1A)

How long has I25.9 existed?

I25.9 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 I25.9?

ICD-10-CM declares these codes mutually exclusive with I25.9 — exactly one of each pair can be correct for a given encounter.

Which conditions are coded to I25.9?

What other codes are in the I25 family? (8)