I20.9 ICD-10-CM Code: Angina pectoris, unspecified
I20.9 is not a CMS-HCC payment code. MEAT criteria · RAF calculator · HCC coding software
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FY 2026 Apr update / Diseases of the circulatory system (I00-I99) / Ischemic heart diseases (I20-I25)
I20.9
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceAngina pectoris, unspecified
Chest pain caused by reduced blood flow to the heart when the specific type or pattern of angina is not documented or cannot be determined.
Buddy Insight
Unspecified angina pectoris is a catch-all code that signals incomplete documentation of ischemic chest pain.
CMS-HCC V28
N/A—
Not mapped
CMS-HCC V24
MappedHCC 88
RAF 0.135
ACA/HHS
N/A—
Not mapped
ESRD/PACE
MappedHCC 88
RAF 0.043
RXHCC
MappedHCC 188
RAF 0.052
Code Book Path
Inclusion Terms
Official- Angina NOS
- Anginal syndrome
- Cardiac angina
- Ischemic chest pain
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for I20.9 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for I20.9 in this effective period.
Excludes 1
Official- angina pectoris with atherosclerotic heart disease of native coronary arteries (I25.1-)
- atherosclerosis of coronary artery bypass graft(s) and coronary artery of transplanted heart with angina pectoris (I25.7-)
- postinfarction angina (I23.7)
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for I20.9 in this effective period.
Use Additional
Official- code to identify:
- exposure to environmental tobacco smoke (Z77.22)
- history of tobacco dependence (Z87.891)
- occupational exposure to environmental tobacco smoke (Z57.31)
- tobacco dependence (F17.-)
Code Also
OfficialICD-10-CM does not list Code Also instructions for I20.9 in this effective period.
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →
Is I20.9 an HCC code?
Yes. I20.9 maps to Angina Pectoris under the V24 model but is not retained in V28.
- Code
- I20.9
- Description
- Angina pectoris, unspecified
- HCC (V28)
- No CMS-HCC V28 mapping
- RAF
- —
- Billable
- Yes
- Payment year
- 2026
HCC Category Mapping
Each model's RAF is its CMS base weight for that model's standard population, so weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.
Work I20.9 in the Code Book — tabular path, V28 RAF, and MEAT checklist →
MEAT Criteria for I20.9
For I20.9 to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically, it has to be re-documented and supported each calendar year.
- MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
- EEvaluate: test results, medication response, or physical findings reviewed by the provider
- AAssess: explicit mention in the assessment or plan with acknowledgment of status
- TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis
Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed I20.9 during that encounter, not just copy-forwarded from a problem list.
Coder workflow notes
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What This Code Means
I20.9 is the ICD-10-CM diagnosis code for angina pectoris, unspecified. Chest pain caused by reduced blood flow to the heart when the specific type or pattern of angina is not documented or cannot be determined. I20.9 sits in the ICD-10-CM chapter for diseases of the circulatory system (i00-i99), within the section covering ischemic heart diseases (i20-i25).
Under the older CMS-HCC V24 model, I20.9 maps to Angina Pectoris (HCC 88) with a community, non-dual, aged base RAF weight of 0.135. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.
This is a default code used only when the type of angina cannot be specified from the medical record. Because I20.9 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for I20.9 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This is a default code used only when the type of angina cannot be specified from the medical record
- •Query the provider for more specific angina classification (stable, unstable, vasospastic) to improve coding specificity
Clinical Significance
Unspecified angina pectoris is a catch-all code that signals incomplete documentation of ischemic chest pain. While it still captures the presence of ischemic heart disease for risk adjustment under V24, it represents a missed opportunity for specificity. Providers should be queried to determine whether the angina is stable, unstable, vasospastic, or refractory.
Documentation Requirements
- ✓Provider statement confirming angina pectoris diagnosis
- ✓Clinical description of chest pain characteristics
- ✓Evidence that more specific angina classification cannot be determined from available documentation
- ✓Diagnostic workup results including electrocardiogram or stress test findings
- ✓Current cardiac medications
Commonly Confused Codes
- •I20.0: Unstable angina: a more specific and higher-acuity diagnosis that maps to HCC 87
- •I20.1: Angina pectoris with documented spasm: requires evidence of coronary spasm
- •I20.89: Other forms of angina pectoris: used when a specific angina type is identified but does not fit standard categories
- •R07.9: Chest pain, unspecified: not appropriate when angina is the established diagnosis
- •I25.119: Atherosclerotic heart disease of native coronary artery with unspecified angina: use when coronary artery disease coexists