2027 ICD-10-CM Diagnosis Code I51.2Rupture of papillary muscle, not elsewhere classified

ICD-10-CM Codes›I00–I99›I30-I5A›I51

ICD-10-CM I51.2
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

I51.2 is a billable ICD-10-CM diagnosis code for rupture of papillary muscle, not elsewhere classified. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 306 through 307. 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 17 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other and ill-defined heart disease.

For Medicare Advantage risk adjustment, I51.2 maps to CMS-HCC Category 229 (Unstable Angina and Other Acute Ischemic Heart Disease) under the V28 model, adding a risk factor of about 0.240 for a community, non-dual, aged beneficiary in payment year 2027.

Code Identity

ICD-10-CM Code
I51.2
Billable Status
Yes — Valid for Submission
Code Describes
Rupture of papillary muscle, not elsewhere classified
Short Description
Rupture of papillary muscle, not elsewhere classified
Same as the full description in the CMS dataset.
Parent Code
Complications and ill-defined descriptions of heart disease

Code Classification

ChapterI00–I99Diseases of the circulatory system
SectionI30-I5AOther forms of heart disease
CategoryI51Complications and ill-defined descriptions of heart disease
This CodeI51.2Rupture of papillary muscle, not elsewhere classified

Medicare Risk Adjustment (HCC)Billing

I51.2 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.

CMS-HCC V28 Category (Payment Model)
HCC 229— Unstable Angina and Other Acute Ischemic Heart Disease
Payment HCC · PY 2027 one of 25 ICD-10-CM codes in this category
Risk Adjustment Factor (RAF) Weight
+0.240
community, non-dual, aged · ranges 0.240–0.458 across segments
Hierarchy
Superseded by HCC 228
a more severe related category takes the payment when both are reported
Prior Model (CMS-HCC V24)
HCC 86
V24 retired V28 pays 100% of MA risk scores since PY 2026
Other CMS Models
PACE (CMS-HCC V22): HCC 86 · ESRD (V21): HCC 86 · ESRD (V24): HCC 86
ESRD V21 weights: 0.131 dialysis, 0.258–0.392 functioning graft · ESRD V24 weights: 0.151 dialysis, 0.219–0.534 functioning graft
Part D (RxHCC)
RxHCC 188 — Coronary Artery Disease
also risk-adjusts in the Part D prescription drug model (V08)

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 mitral regurgitation
  • Acute mitral regurgitation from papillary muscle rupture
  • Mitral papillary muscle abnormality
  • Mitral papillary muscle rupture
  • Postprocedural mitral valve regurgitation
  • Postprocedural mitral valve regurgitation due to papillary muscle and chordal rupture
  • Rupture of left atrioventricular valve papillary muscle
  • Rupture of papillary muscle
  • Rupture of right atrioventricular valve papillary muscle
  • Rupture of tricuspid valve papillary muscle
  • Structural abnormality of trabeculae carnea of left ventricle
  • Structural abnormality of trabeculae carnea of right ventricle
  • Tricuspid papillary muscle abnormality

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to I51.2: its own notes plus those printed at I51 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.

  • rupture of papillary muscle as current complication following acute myocardial infarction (I23.5)

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.

From I51 Complications and ill-defined descriptions of heart disease applies to 10 codes
  • heart disease specified as rheumatic (I00-I09)
From Chapter 9 (I00-I99) Diseases of the circulatory system applies to 1,433 codes
  • 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.-)

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name I51.2, its category, or a range that includes it.

Excludes1 1

These codes carry an Excludes1 note naming I51.2: they are not reported together with it, unless the two conditions are unrelated.

  • I23.5 Rupture of papillary muscle as current complication following acute myocardial infarction
    rupture of papillary muscle not specified as current complication following acute myocardial infarction (I51.2)

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.

CCSR CIR015
Other and ill-defined heart disease
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Heart Diseases

Heart disease is a general term that includes many types of heart problems. It's a type of cardiovascular disease, which means heart and blood vessel disease.

The full article covers:

  • What is heart disease?
  • What are the types of heart disease?
  • What causes heart diseases?
  • Who is more likely to develop heart diseases?
  • What are the symptoms of heart disease?
  • How are heart diseases diagnosed?
  • What are the treatments for heart disease?
  • Can heart diseases be prevented?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert I51.2 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
429.6 Papillary muscle rupture
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About I51.2Overview

What is the ICD-10 code for rupture of papillary muscle, not elsewhere classified?

The ICD-10-CM code for rupture of papillary muscle, not elsewhere classified is I51.2 (sometimes written as I512). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is I51.2 (Complications and ill-defined descriptions of heart disease) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report rupture of papillary muscle, not elsewhere classified on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does I51.2 group to?

When rupture of papillary muscle, not elsewhere classified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 306, 307, with relative weights from 0.9146 to 1.5457 depending on complications. Higher weights mean higher Medicare reimbursement.

Is I51.2 a CC or MCC?

CMS lists I51.2 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 17 closely related codes in its exclusion list.

Can I51.2 be reported with I23.5?

Not as a rule. The Excludes1 note on I51.2 lists "rupture of papillary muscle as current complication following acute myocardial infarction (I23.5)". 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 I51.2?

I51.2 (rupture of papillary muscle, not elsewhere classified) maps to CMS-HCC Category 229 (Unstable Angina and Other Acute Ischemic Heart Disease), commonly written as HCC 229, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 86 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 188.

Does I51.2 risk-adjust for Medicare Advantage payment?

Yes. When documented and reported on a Medicare Advantage encounter, I51.2 adds a risk adjustment factor of about 0.240 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.240 to 0.458 depending on the payment segment). A more severe related category (HCC 228) supersedes it when both are reported. See the full factor table on the HCC 229 category page.