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I20.2 ICD-10-CM Code: Refractory angina pectoris

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Coding at a Glance

Tabular directives
3 Excludes1 · 6 use-additional codes · 1 code-also instruction
Risk adjustment
CMS-HCC V22 category 88 · RxHCC V08 category 188

Inpatient Payment Groups (MS-DRG)

Potential MS-DRG participation — not a DRG assignment.

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v43, Appendix B.

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for I20.2 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2026Effective: October 1, 2025

Notes without a marker are published on I20.2 itself; “inherited from” names the category or block whose note applies here.

Excludes1 — Not Coded Here

Conditions generally not reported together with this code (Excludes1) -- an error unless the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Source: inherited from I20

Code Also

Additional codes that may be required to fully describe the encounter.

  • the presence of hypertension (I10-I1A)

Source: inherited from I20-I25

Use Additional Code

Supplementary codes the tabular list directs you to add.

  • Use additional 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.-)
  • tobacco use (Z72.0)

Source: inherited from I20

Coder workflow for I20.2

MedCoder structured workflow — derived from this code’s own official record

Before you code I20.2

  1. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with I20.2. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).

    See the official tabular notes

Choose the right path

  1. Does the documentation support a condition named in I20.2’s Excludes1 note?
    Yes → Do not simply proceed: review the excluded code. Both are reported only when the record shows the two conditions are unrelated.
    No → Continue.

    ReviewI25.1, I25.7, I23.7

Consider I20.2. Then work the Use Additional Code note and review the Code Also note, and confirm the code is valid for the date of service in the Verify section.

Documentation check

The provider’s diagnostic statement
Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).
The conditions the Use Additional Code note names
Reported with this code when documented; a conditional instruction (“if applicable”, “if known”) applies only when the record supports it.

Official instructions as workflow

  • Excludes1 — check before selecting I20.2(3 notes)

    Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with I20.2: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

    CompareI25.1, I25.7, I23.7

    See the official tabular notes · Guidelines I.A.12.a

  • Use Additional Code — after identifying I20.2(6 notes)

    Coding workflow: Check whether the documentation supports the additional code(s) the note names, and report them with I20.2 when it does. Where the instruction is conditional (“if applicable”, “if known”), it applies only when the record documents the condition.

    ReviewZ77.22, Z87.891, Z57.31, F17, Z72.0

    See the official tabular notes · Guidelines I.A.13

  • Code Also — related condition(1 note)

    Coding workflow: Review the related condition when both are documented and the instruction applies. A Code Also note does not fix sequencing; the order follows the circumstances of the encounter.

    See the official tabular notes · Guidelines I.A.17

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

Documentation: Both the condition I20.2 describes and a condition named in its Excludes1 note are documented for the same encounter.

Coding question: Can both codes be reported?

Path: Review the Excludes1 note and the excluded code, and look for a provider statement on whether the two conditions are related.

Reason: Excludes1 means the two are not coded together; the exception is when the record shows the conditions are unrelated to each other (Guidelines I.A.12.a).

ReviewI25.1, I25.7, I23.7

Documentation: A condition the Use Additional Code note names is documented.

Coding question: Is a second code reported with I20.2?

Path: Review the Use Additional Code note and the code it names.

Reason: The additional code is reported when the record documents the condition; a conditional instruction applies only when its condition is met (Guidelines I.A.13).

ReviewZ77.22, Z87.891, Z57.31, F17, Z72.0

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Code Overview

Refractory angina pectoris is a billable ICD-10-CM diagnosis code (I20.2).

MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.

Indexed Clinical Terms (1)

Official source data — entries quoted as published, in the Index’s own lookup phrasing

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code. These are alphabetic-index entries shown as the Index writes them — lookup phrasing, not necessarily the wording of a final diagnosis.

Decision Points

The directives on this code's own record, as a pre-claim checklist.

  1. 6 Use Additional Code instructions — report the named additional code(s) when the documentation supports them. See the Use Additional Code notes
  2. 1 Code Also note — a second code may apply; the guidelines leave its sequencing to the circumstances of the encounter. See the Code Also notes
  3. 3 Excludes1 entries — codes named there are generally not reported together with this code (Guidelines I.A.12.a). See the Excludes1 notes

Checklist rows are derived from this code's own official directives; the wording of each check is MedCoder editorial. The official notes themselves are in the sections each row links to.

Verify Before Coding

  • CC as a secondary diagnosis (FY2026). Can raise the stay's MS-DRG severity tier.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder structured relationships — computed from published CMS and AHRQ datasets

Other codes that name I20.2 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 1 Excludes1 note: I24 — Other acute ischemic heart diseases (via I20.-).

These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.

MS-DRG Grouper Relationships (FY2026)

Potential MS-DRG participation — not a DRG assignment.

FY2026 MS-DRG: CC — Complication or Comorbidity. Reported as a secondary diagnosis, this code raises the stay's MS-DRG severity tier — except when the principal diagnosis is one of 81 clinically related codes on its CMS exclusion list.

Named in the grouper logic of 1 MS-DRG: DRG 311 (MDC 05).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):CIR011 — Coronary atherosclerosis and other heart disease (default).

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same clinical process (MS-DRG)

Acts as CC — raises the severity of other admissions. CMS groups these diagnoses into one MS-DRG principal-diagnosis exclusion process — a CC/MCC on this list never raises severity when the principal diagnosis is also on it.

I20.0 — Unstable angina, I20.1 — Angina pectoris with documented spasm, I20.81 — Angina pectoris with coronary microvascular dysfunction, I20.89 — Other forms of angina pectoris, I20.9 — Angina pectoris, unspecified, I21.01 — ST elevation (STEMI) myocardial infarction involving left main coronary artery, I21.02 — ST elevation (STEMI) myocardial infarction involving left anterior descending coronary artery, I21.09 — ST elevation (STEMI) myocardial infarction involving other coronary artery of anterior wall, I21.11 — ST elevation (STEMI) myocardial infarction involving right coronary artery, I21.19 — ST elevation (STEMI) myocardial infarction involving other coronary artery of inferior wall, I21.21 — ST elevation (STEMI) myocardial infarction involving left circumflex coronary artery, I21.29 — ST elevation (STEMI) myocardial infarction involving other sites, I21.3 — ST elevation (STEMI) myocardial infarction of unspecified site, I21.4 — Non-ST elevation (NSTEMI) myocardial infarction, I21.9 — Acute myocardial infarction, unspecified, I21.A1 — Myocardial infarction type 2, I21.A9 — Other myocardial infarction type, I21.B — Myocardial infarction with coronary microvascular dysfunction, I22.0 — Subsequent ST elevation (STEMI) myocardial infarction of anterior wall, I22.1 — Subsequent ST elevation (STEMI) myocardial infarction of inferior wall, +60 more

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Coronary atherosclerosis and other heart disease).

I20.0 — Unstable angina, I20.1 — Angina pectoris with documented spasm, I20.8 — Other forms of angina pectoris, I20.81 — Angina pectoris with coronary microvascular dysfunction, I20.89 — Other forms of angina pectoris, I20.9 — Angina pectoris, unspecified, I24.0 — Acute coronary thrombosis not resulting in myocardial infarction, I24.8 — Other forms of acute ischemic heart disease, I24.81 — Acute coronary microvascular dysfunction, I24.89 — Other forms of acute ischemic heart disease, I24.9 — Acute ischemic heart disease, unspecified, I25.10 — Atherosclerotic heart disease of native coronary artery without angina pectoris, I25.110 — Atherosclerotic heart disease of native coronary artery with unstable angina pectoris, I25.111 — Atherosclerotic heart disease of native coronary artery with angina pectoris with documented spasm, I25.112 — Atherosclerotic heart disease of native coronary artery with refractory angina pectoris, I25.118 — Atherosclerotic heart disease of native coronary artery with other forms of angina pectoris, I25.119 — Atherosclerotic heart disease of native coronary artery with unspecified angina pectoris, I25.2 — Old myocardial infarction, I25.5 — Ischemic cardiomyopathy, I25.6 — Silent myocardial ischemia, +47 more

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main term “Angina”; these codes share that main term but sit in a different category of the Tabular List.

A36.0 — Pharyngeal diphtheria (malignant diphtheritic), A36.2 — Laryngeal diphtheria (stridulous, diphtheritic), A69.1 — Other Vincent's infections (Vincent's), B08.5 — Enteroviral vesicular pharyngitis (aphthous), I23.7 — Postinfarction angina (post-infarctional), I73.9 — Peripheral vascular disease, unspecified (cruris), J05.0 — Acute obstructive laryngitis [croup] (croupous), J36 — Peritonsillar abscess (tonsil), J37.0 — Chronic laryngitis (exudative, chronic), K12.2 — Cellulitis and abscess of mouth (Ludwig's), K55.1 — Chronic vascular disorders of intestine (abdominal)

Lab tests where this diagnosis supports Medicare coverage (NCD)

Medicare's National Coverage Determination (NCD) program lists this diagnosis as medical justification for these lab tests.

Lipid Panel, Prothrombin Time Test and INR (PT/INR)

Contextual Map

Every relationship of I20.2 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run I20.2 with this related code in Claim Check

Hierarchy

Referenced by Excludes1 notes

Clinical classification (CCSR)

MS-DRG Grouper

  • CC — Complication or Comorbidity [MS-DRG severity]: “As a secondary diagnosis this code can raise the stay's MS-DRG severity tier (CC).”— CMS MS-DRG Definitions Manual (Appendix C) · FY2026
  • DRG 311 — ANGINA PECTORIS[MS-DRG]: “ANGINA PECTORIS (MDC 05)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026

MDC crossing

  • MDC 05 — Diseases and Disorders of the Circulatory System[MDC crossing]: “Diseases and Disorders of the Circulatory System — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs. 17,209 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2026

Index entries

  • Angina (attack) (cardiac) (chest) (heart) (pectoris) (syndrome) (vasomotor), refractory[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026

Nearest codes

Change history

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data
CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page
Inpatient payment groups Official source data
CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v43 Release, file and checksum · Publisher’s page
Change history and date-of-service validity Official source data
CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
Comparisons, relationships and the contextual map MedCoder structured relationship
Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
Summary and FAQ answers MedCoder explanation
Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Cite this page

Reference this page in a research guide, syllabus or article. The release is included because code content changes each year.

MedCoder.ai. "I20.2 — Refractory angina pectoris." ICD-10-CM FY2026. https://medcoder.ai/icd10/code/i20.2-refractory-angina-pectoris

Change history

  • FY2023 — October 1, 2022
    Added to the code set
    Refractory angina pectoris
    FY2023 changes

Nearest Codes in This Family

Official ICD-10-CM classifications closest to I20.2 in its code family, with their registry titles.

View all codes in the I20 family