2027 ICD-10-CM Diagnosis Code I25.6Silent myocardial ischemia
ICD-10-CM Codes›I00–I99›I20-I25›I25
- Billable — Valid for Submission
- Chronic Condition
I25.6 is a billable ICD-10-CM diagnosis code for silent myocardial ischemia. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 302 through 303. Coders also document this condition as silent coronary vasospastic disease. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Coronary atherosclerosis and other heart disease.
I25.6 does not risk-adjust for Medicare Advantage under the CMS-HCC V28 model. It still risk-adjusts in the RxHCC Part D (V08) category 188 for payment year 2027.
This medical diagnosis code is frequently used in Cardiology medical specialties to designate conditions such selected atherosclerosis, ischemia, and infarction.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
I25.6 does not risk-adjust for Medicare Advantage under the CMS-HCC V28 model, but it maps to payment categories in the other CMS models shown below.
Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Silent coronary vasospastic disease
- Silent myocardial infarction
- Silent myocardial ischemia
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to I25.6: its own notes plus those printed at I25, block I20-I25, and Chapter 9. A note printed at a category, block or chapter applies to every code under it.
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may 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
A second code may be needed to fully describe the condition; the note gives no sequencing direction.
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name I25.6, its category, or a range that includes it.
Excludes2 2
These codes carry an Excludes2 note naming I25.6: its condition is not part of those codes, and both may be reported when the patient has both.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Disease, diseased See Also: Syndrome;
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Coronary Artery Disease
Coronary artery disease (CAD) is the most common type of heart disease in the United States and a leading cause of death for both men and women.
The full article covers:
- What is coronary artery disease?
- What causes coronary artery disease?
- What are the types of coronary artery disease?
- Who is more likely to have coronary artery disease?
- What are symptoms of coronary artery disease?
- What other problems does coronary artery disease cause?
- How is coronary artery disease diagnosed?
- What are the treatments for coronary artery disease?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert I25.6 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About I25.6Overview
What is the ICD-10 code for silent myocardial ischemia?
The ICD-10-CM code for silent myocardial ischemia is I25.6 (sometimes written as I256). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is I25.6 (Chronic ischemic heart disease) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report silent myocardial ischemia on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does I25.6 group to?
When silent myocardial ischemia is the principal diagnosis on an inpatient stay, it groups to MS-DRG 302, 303, with relative weights from 0.6610 to 1.1993 depending on complications. Higher weights mean higher Medicare reimbursement.
Does I25.6 need an additional code?
When the condition applies, yes. The Use Additional Code note at I25, which applies to I25.6, reads: 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.-); and 1 more listed in the Instructional Notes section. The additional code is reported after I25.6.
What is the ICD-9 equivalent of I25.6?
Under the General Equivalence Mappings, silent myocardial ischemia converts to ICD-9-CM 414.8 (chr ischemic hrt dis NEC). The mapping is approximate, so confirm the match fits the documentation.
Does I25.6 risk-adjust for Medicare Advantage payment?
Not for Medicare Advantage: I25.6 maps to no category in the CMS-HCC V28 model. It still risk-adjusts in the RxHCC Part D (V08) category 188 (Coronary Artery Disease).
