FY2027 ICD-10-CM reference
I31.31: Malignant pericardial effusion in diseases classified elsewhere
By the HCC Buddy Coding Team
The official ICD-10-CM descriptor is Malignant pericardial effusion in diseases classified elsewhere. The FY2027 annual edition starts October 1, 2026. Check the edition that applies to the encounter or inpatient discharge, including any April update.
Billable code. Verified against the official FY2027 order file.
FY2027 Tabular instructions
Instructions below include applicable chapter, section and parent-code notes. Each note identifies where it appears in the official source.
Excludes2
certain conditions originating in the perinatal period (P04-P96)
Source: I00-I99 (chapter, inherited).
Excludes2
certain infectious and parasitic diseases (A00-B99)
Source: I00-I99 (chapter, inherited).
Excludes2
complications of pregnancy, childbirth and the puerperium (O00-O9A)
Source: I00-I99 (chapter, inherited).
Excludes2
congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
Source: I00-I99 (chapter, inherited).
Excludes2
endocrine, nutritional and metabolic diseases (E00-E88)
Source: I00-I99 (chapter, inherited).
Excludes2
injury, poisoning and certain other consequences of external causes (S00-T88)
Source: I00-I99 (chapter, inherited).
Excludes2
neoplasms (C00-D49)
Source: I00-I99 (chapter, inherited).
Excludes2
symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
Source: I00-I99 (chapter, inherited).
Excludes2
systemic connective tissue disorders (M30-M36)
Source: I00-I99 (chapter, inherited).
Excludes2
transient cerebral ischemic attacks and related syndromes (G45.-)
Source: I00-I99 (chapter, inherited).
Excludes1
diseases of pericardium specified as rheumatic (I09.2)
Source: I31 (category, inherited).
Excludes1
postcardiotomy syndrome (I97.0)
Source: I31 (category, inherited).
Excludes1
traumatic injury to pericardium (S26.-)
Source: I31 (category, inherited).
Excludes1
acute pericardial effusion (I30.9)
Source: I31.3 (self, inherited).
Code first
underlying neoplasm (C00-D49)
Source: I31.31 (self, direct).
Compare the FY2027 additions, removals and billable-status changes
What does I31.31 mean in FY2027?
The official ICD-10-CM descriptor is Malignant pericardial effusion in diseases classified elsewhere. The FY2027 annual edition starts October 1, 2026. Check the edition that applies to the encounter or inpatient discharge, including any April update.
Is I31.31 billable in FY2027?
The FY2027 order file marks I31.31 as billable. Check the complete Tabular instructions and documentation before assigning it.
Does I31.31 map to an HCC?
In the CMS 2027 Initial ICD-10-CM Mappings (payment year 2027, 2026 dates of service), I31.31 maps to CMS-HCC V28 HCC 17 (Cancer Metastatic to Lung, Liver, Brain, and Other Organs; Acute Myeloid Leukemia Except Promyelocytic). For 2027 dates of service, CMS has not yet published the payment year 2028 mappings. Under the PY2026 CMS mapping; CMS 2027 initial file unchanged: no ESRD category; no RxHCC category. Coefficients for these models are pending verification for payment year 2027. HHS-HCC: HCC 135 under the HHS-HCC 2026 benefit year mapping (no RAF; HHS-HCC weights vary by metal level). CMS-HCC V24: not used for payment year 2027 Medicare Advantage payment (CMS CY 2027 Rate Announcement). The PACE mapping is still pending verification for FY2027.
Source: CMS FY2027 ICD-10-CM order file. Payment model: CMS CY 2027 Rate Announcement. Read the FY2027 Official Guidelines.
Review the FY2026 April edition