2027 ICD-10-CM Diagnosis Code I50.23Acute on chronic systolic (congestive) heart failure
ICD-10-CM Codes›I00–I99›I30-I5A›I50
- Billable — Valid for Submission
- MCC — Major Complication or Comorbidity
- Risk Adjusts — HCC 224
- Chronic Condition
I50.23 is a billable ICD-10-CM diagnosis code for acute on chronic systolic (congestive) heart failure. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 291 through 293, 791, 793. As a secondary diagnosis, it counts as a major complication or comorbidity (MCC) and places an inpatient stay in the highest severity level of its MS-DRG family. It does not count, however, when the principal diagnosis is one of 32 closely related codes. Coders also document this condition as acute exacerbation of chronic heart failure. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Heart failure.
For Medicare Advantage risk adjustment, I50.23 maps to CMS-HCC Category 224 (Acute on Chronic Heart Failure) under the V28 model, adding a risk factor of about 0.360 for a community, non-dual, aged beneficiary in payment year 2027.
This medical diagnosis code is frequently used in Cardiology medical specialties to designate conditions such heart failure.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
I50.23 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2027.
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.
- Acute exacerbation of chronic heart failure
- Acute on chronic systolic heart failure
- Acute systolic heart failure
- Chronic systolic heart failure
- Decreased cardiac ejection fraction
- Decreased cardiac function
- Heart failure with reduced ejection fraction
- Reduced ejection fraction co-occurrent and due to acute heart failure
- Reduced ejection fraction co-occurrent and due to acute on chronic heart failure
- Reduced ejection fraction co-occurrent and due to chronic heart failure
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to I50.23: its own notes plus those printed at I50.2, I50, and Chapter 9. A note printed at a category, block or chapter applies to every code under it.
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
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 First
The underlying condition named in the note is sequenced before this code.
- heart failure complicating abortion or ectopic or molar pregnancy (O00-O07, O08.8)
- heart failure due to hypertension (I11.0)
- heart failure due to hypertension with chronic kidney disease (I13.-)
- heart failure following surgery (I97.13-)
- obstetric surgery and procedures (O75.4)
- rheumatic heart failure (I09.81)
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 I50.23, its category, or a range that includes it.
Includes 1
These notes mention I50.23.
Excludes2 1
These codes carry an Excludes2 note naming I50.23: its condition is not part of those codes, and both may be reported when the patient has both.
Code First 1
These codes say to code first a condition named in the note, and I50.23 is one of the conditions named.
Use Additional Code 5
These codes say to use an additional code from the note, and I50.23 is one of the codes named.
- I09.81 Rheumatic heart failurecode to identify type of heart failure (I50.-) names I50.-, which includes this code
- I11.0 Hypertensive heart disease with heart failurecode to identify type of heart failure (I50.-) names I50.-, which includes this code
- I13.0 Hypertensive heart and chronic kidney disease with heart failure and stage 1 through stage 4 chronic kidney disease, or unspecified chronic kidney diseasecode to identify type of heart failure (I50.-) names I50.-, which includes this code
- I13.2 Hypertensive heart and chronic kidney disease with heart failure and with stage 5 chronic kidney disease, or end stage renal diseasecode to identify type of heart failure (I50.-) names I50.-, which includes this code
- I97.13 Postprocedural heart failurecode to identify the heart failure (I50.-) names I50.-, which includes this code
Code Also 7
These codes say I50.23 may also be needed to fully describe the condition. The note gives no sequencing direction.
- E83.820 Generalized arterial calcification of infancy with unspecified genetic causalityheart failure (I50.-) names I50.-, which includes this code
- E83.821 ENPP1 deficiency causing generalized arterial calcification of infancyheart failure (I50.-) names I50.-, which includes this code
- E83.823 ABCC6 deficiency causing generalized arterial calcification of infancyheart failure (I50.-) names I50.-, which includes this code
- I16.1 Hypertensive emergencyacute pulmonary edema (left and/or right ventricular failure) (J81.0, I50.-) names I50.-, which includes this code
- I50.814 Right heart failure due to left heart failure
- I50.82 Biventricular heart failure
- I50.84 End stage heart failure
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Acute on Chronic Systolic Congestive Heart Failure
acute decompensation of chronic systolic congestive heart failure.Heart Failure, Systolic
heart failure caused by abnormal myocardial contraction during systole leading to defective cardiac emptying.
Patient EducationClinical
Heart Failure
Heart failure means that your heart can't pump enough oxygen-rich blood to meet your body's needs. Heart failure doesn't mean that your heart has stopped or is about to stop beating. But without enough blood flow, your organs may not work well, which can cause serious problems.
The full article covers:
- What is heart failure?
- What causes heart failure?
- Who is more likely to develop heart failure?
- What are the symptoms of heart failure?
- What other problems does heart failure cause?
- How is heart failure diagnosed?
- What are the treatments for heart failure?
- Can heart failure be prevented?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert I50.23 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About I50.23Overview
What is the ICD-10 code for acute on chronic systolic (congestive) heart failure?
The ICD-10-CM code for acute on chronic systolic (congestive) heart failure is I50.23 (sometimes written as I5023). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is I50.23 (Systolic (congestive) heart failure) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report acute on chronic systolic (congestive) heart failure on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does I50.23 group to?
When acute on chronic systolic (congestive) heart failure is the principal diagnosis on an inpatient stay, it groups to MS-DRG 292, 793, 293, 791, 291, with relative weights from 0.5460 to 4.2192 depending on complications. Higher weights mean higher Medicare reimbursement.
Is I50.23 a CC or MCC?
CMS lists I50.23 as an MCC (major complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it places the inpatient stay in the highest-weighted DRG of its severity family. It does not count when the principal diagnosis is one of the 32 closely related codes in its exclusion list.
Can I50.23 be reported with a code from I50.4?
Not as a rule. The Excludes1 note at I50.2, which applies to I50.23, lists "combined systolic (congestive) and diastolic (congestive) heart failure (I50.4-)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
What HCC is I50.23?
I50.23 (acute on chronic systolic (congestive) heart failure) maps to CMS-HCC Category 224 (Acute on Chronic Heart Failure), commonly written as HCC 224, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 85 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. In the Part D prescription drug model it maps to RxHCC 186.
Does I50.23 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, I50.23 adds a risk adjustment factor of about 0.360 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.217 to 0.537 depending on the payment segment). A more severe related category (HCC 221, HCC 222, and HCC 223) supersedes it when both are reported. See the full factor table on the HCC 224 category page.
