What is ICD-10 code I25.700?

I25.700 is the ICD-10-CM diagnosis code for Atherosclerosis of coronary artery bypass graft(s), unspecified, with unstable angina pectoris. Buildup of plaque in coronary artery bypass grafts causing unstable chest pain that occurs unpredictably and may indicate a heart attack risk. I25.700 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. I25.700 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. I25.700 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. I25.700 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

What is the V28 vs V24 difference for I25.700?

CMS phased in the V28 risk adjustment model over payment years 2024 (33%), 2025 (67%), and 2026 (100%), replacing V24. V28 consolidates HCC categories, removes some lower-acuity conditions, and recalibrates RAF weights across the entire model. For I25.700, V28 maps to Unstable Angina and Other Acute Ischemic Heart Disease at RAF 0.000 while V24 mapped to Unstable Angina and Other Acute Ischemic Heart Disease at RAF 0.274. Both models can still appear in legacy data and in payer-specific lookback periods.

What should coders know when reporting I25.700?

Verify documentation specifies 'unstable angina' to distinguish from other angina types Confirm the bypass graft type is unspecified before assigning this code rather than more specific graft codes Because I25.700 maps to a payment HCC, the documentation must also satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's risk adjustment score.

I25.700 ICD-10 Code: Atherosclerosis of coronary

ICD-10-CM Code View

HCC Buddy Code Card

Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.

Code lookupI25.700Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Diseases of the circulatory system (I00-I99) / Ischemic heart diseases (I20-I25)

I25.700

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Atherosclerosis of coronary artery bypass graft(s), unspecified, with unstable angina pectoris

Buildup of plaque in coronary artery bypass grafts causing unstable chest pain that occurs unpredictably and may indicate a heart attack risk.

Buddy Insight

CMS-HCC V28

Mapped

HCC 229

Unstable Angina and Other Acu...

RAF 0.0

CMS-HCC V24

Mapped

HCC 87

Unstable Angina and Other Acu...

RAF 0.274

ACA/HHS

Not risk-adjusted for this model/period.

RAF 0

ESRD/PACE

Mapped

HCC 87

Unstable Angina and Other Acu...

RAF 0.0

RXHCC

Mapped

HCC 188

Coronary Artery Disease and A...

RAF 0.0

Code Trumping

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Code Book Path

Official

I25.7Atherosclerosis of coronary artery bypass graft(s) and coronary artery of transplanted heart with angina pectoris

I25.70Atherosclerosis of coronary artery bypass graft(s), unspecified, with angina pectoris

I25.700Atherosclerosis of coronary artery bypass graft(s), unspecified, with unstable angina pectoris

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for I25.700 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for I25.700 in this effective period.

Related Child Codes

Official

I25.701Atherosclerosis of coronary artery bypass graft(s), unspecified, with angina pectoris with documented spasm

I25.702Atherosclerosis of coronary artery bypass graft(s), unspecified, with refractory angina pectoris

I25.708Atherosclerosis of coronary artery bypass graft(s), unspecified, with other forms of angina pectoris

I25.709Atherosclerosis of coronary artery bypass graft(s), unspecified, with unspecified angina pectoris

Includes

Official

ICD-10-CM does not list Includes notes for I25.700 in this effective period.

Excludes 1

Official

unstable angina pectoris without atherosclerosis of coronary artery bypass graft (I20.0)

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for I25.700 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for I25.700 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for I25.700 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Documentation of atherosclerosis affecting coronary artery bypass graft(s)

History of prior coronary artery bypass graft surgery

Unstable angina explicitly documented (new onset, crescendo, or rest angina)

Bypass graft type if known (saphenous vein, internal mammary artery, other)

MEAT Support

HCC Buddy guidance

Documentation of atherosclerosis affecting coronary artery bypass graft(s)

History of prior coronary artery bypass graft surgery

Unstable angina explicitly documented (new onset, crescendo, or rest angina)

Bypass graft type if known (saphenous vein, internal mammary artery, other)

Audit Caution

HCC Buddy guidance

Using native coronary artery codes when the disease is in the bypass graft

Assigning this unspecified graft type code when the specific graft type (saphenous vein, internal mammary artery) is documented

Not confirming the patient has a history of coronary artery bypass graft surgery before using bypass graft codes

Coding stable angina instead of unstable when documentation supports unstable presentation

Common Mistakes

HCC Buddy guidance

I25.110 — Atherosclerotic heart disease of native coronary artery with unstable angina: for native vessels, not grafts

I25.710 — Atherosclerosis of autologous vein coronary artery bypass graft with unstable angina: more specific graft type

I25.810 — Atherosclerosis of coronary artery bypass graft without angina: no angina documented

I25.701 — Same condition with documented spasm: different angina type

Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.

Is I25.700 an HCC code?

Yes. I25.700 maps to Unstable Angina and Other Acute Ischemic Heart Disease under the CMS-HCC V28 risk adjustment model (and Unstable Angina and Other Acute Ischemic Heart Disease under V24).

HCC Category Mapping

V28HCC 229, Unstable Angina and Other Acute Ischemic Heart Disease

0.000

V24HCC 87, Unstable Angina and Other Acute Ischemic Heart Disease

0.274

ESRDHCC 87, Unstable Angina and Other Acute Ischemic Heart Disease

0.000

RxHCCHCC 188, Coronary Artery Disease and Angina

0.000

RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. 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.

MEAT Criteria for I25.700

For I25.700to 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 I25.700 during that encounter, not just copy-forwarded from a problem list.

What This Code Means

I25.700 is the ICD-10-CM diagnosis code for atherosclerosis of coronary artery bypass graft(s), unspecified, with unstable angina pectoris. Buildup of plaque in coronary artery bypass grafts causing unstable chest pain that occurs unpredictably and may indicate a heart attack risk. I25.700 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 CMS-HCC V28 risk adjustment model, I25.700 maps to Unstable Angina and Other Acute Ischemic Heart Disease (HCC 229) with a community, non-dual, aged base RAF weight of 0.000. Under the older V24 model, I25.700 mapped to the same category but with a base RAF weight of 0.274, V28 recalibrated weights across the entire model. 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.

Verify documentation specifies 'unstable angina' to distinguish from other angina types. Because I25.700 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 I25.700 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Verify documentation specifies 'unstable angina' to distinguish from other angina types
•Confirm the bypass graft type is unspecified before assigning this code rather than more specific graft codes

Clinical Significance

This combination code captures atherosclerosis of coronary artery bypass grafts with unstable angina, indicating that the patient's bypass grafts have developed plaque disease and the patient is experiencing high-risk anginal symptoms. This is particularly significant because bypass graft atherosclerosis indicates disease progression after surgical revascularization and may necessitate repeat intervention.

Documentation Requirements

✓Documentation of atherosclerosis affecting coronary artery bypass graft(s)
✓History of prior coronary artery bypass graft surgery
✓Unstable angina explicitly documented (new onset, crescendo, or rest angina)
✓Bypass graft type if known (saphenous vein, internal mammary artery, other)
✓Diagnostic evidence (angiography showing graft disease)
✓Current treatment plan

Excludes 1, Do NOT code together

unstable angina pectoris without atherosclerosis of coronary artery bypass graft (I20.0)

Commonly Confused Codes

•I25.110 — Atherosclerotic heart disease of native coronary artery with unstable angina: for native vessels, not grafts
•I25.710 — Atherosclerosis of autologous vein coronary artery bypass graft with unstable angina: more specific graft type
•I25.810 — Atherosclerosis of coronary artery bypass graft without angina: no angina documented
•I25.701 — Same condition with documented spasm: different angina type