I70.661 ICD-10-CM Code: Atherosclerosis of nonbiological bypass graft(s) of the extremities with gangrene, right leg

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for I70.661 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 I70.661 itself; “inherited from” names the category or block whose note applies here.

Coder workflow for I70.661

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

Before you code I70.661

1. Laterality is coded in this family. Confirm the side documented — right, left, or bilateral — and select the matching code (this page’s code: right). The unspecified-side code applies only when the record states no side. Laterality is assigned from the documented side; where a bilateral code exists and both sides are documented, it is used instead of two unilateral codes (Guidelines I.B.13).

   ReviewI70.662 · left

   Guide: Laterality coding →

2. I70.661’s title joins a condition with an associated condition or complication. Confirm each component is documented. Where the classification presumes the link through the “with” convention, only a provider statement that the conditions are unrelated defeats it. A combination code is assigned only when it fully identifies the documented conditions; a required second code for the stage, type or manifestation is still reported when the notes ask for it (Guidelines I.B.9, I.A.15).

   Guide: Combination codes →

Choose the right path

1. Is the side documented?
   Yes → Select the code for the documented side (or the bilateral code when both sides are documented and one exists).
   No → Use the unspecified-side code only when the record states no side; a query is the alternative.

   ReviewI70.662 · left

Consider I70.661. Then work the Use Additional Code 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).

Laterality

Right, left or bilateral as documented; unspecified only when the record states no side (Guidelines I.B.13).

The associated condition or complication

Whether the associated condition the title names is documented; the “with” convention presumes some links, and a provider statement that the conditions are unrelated defeats it (Guidelines I.A.15).

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

• Excludes2 — not part of I70.661(8 notes)

  Coding workflow: The conditions named in this note are not included in I70.661. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

  CompareI25.1, I75, I67.2, K55.1, I27.0

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

• Use Additional Code — after identifying I70.661(8 notes)

  Coding workflow: Check whether the documentation supports the additional code(s) the note names, and report them with I70.661 when it does. Where the instruction is conditional (“if applicable”, “if known”), it applies only when the record documents the condition.

  ReviewL97, L98.49, I70.92, Z77.22, Z87.891, Z57.31

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

Coding decision scenarios

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

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.

Indexed Clinical Terms (2)

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.

• Arteriosclerosis, arteriosclerotic (diffuse) (obliterans) (of) (senile) (with calcification), extremities (native arteries), bypass graft, nonbiological graft, leg, right, with, gangrene (and intermittent claudication, rest pain and ulcer)
• Arteriosclerosis, arteriosclerotic (diffuse) (obliterans) (of) (senile) (with calcification), with, critical limb ischemia, bypass graft, nonbiological graft, leg, right, with, gangrene (and intermittent claudication, rest pain, and ulcer)

Don’t confuse I70.661 with…

MedCoder analysis — pairs from this code’s official notes, distinctions written by MedCoder

The codes most likely to be picked instead of I70.661 — named in its own official notes, or sharing its laterality or encounter family — with what separates them and which documentation moves the case. Each links to the full comparison.

• I70.669— Specificity relationship (Review)

  Overlapping diagnoses in the same category.

  Overlapping codes in the same category — the documentation decides which is the more specific fit.

  What moves you there: A record that documents no more than “Atherosclerosis of nonbiological bypass graft(s) of the extremities with gangrene, unspecified extremity” takes I70.669; specificity in the record moves it back here.

  Full comparison: I70.661 vs I70.669 →

• I70.662— Laterality relationship (Review)

  Same condition; these differ only in which side is documented.

  The same condition on the other side; the documented side decides, and a bilateral code, where one exists, replaces the pair when both sides are documented.

  What moves you there: A documented left side moves the case to I70.662.

  Full comparison: I70.661 vs I70.662 →

• I25.1— Excludes2 relationship (Informational)

  Distinct conditions — both may be reported.

  A distinct condition — both may be reported when both are documented.

  What moves you there: Documentation of arteriosclerotic cardiovascular disease adds I25.1; it is not part of this code and both may be reported when both are documented.

  Full comparison: I70.661 vs I25.1 →

• I75— Excludes2 relationship (Informational)

  Distinct conditions — both may be reported.

  A distinct condition — both may be reported when both are documented.

  What moves you there: Documentation of atheroembolism adds I75; it is not part of this code and both may be reported when both are documented.

  Full comparison: I70.661 vs I75 →

• I67.2— Excludes2 relationship (Informational)

  Distinct conditions — both may be reported.

  A distinct condition — both may be reported when both are documented.

  What moves you there: Documentation of cerebral atherosclerosis adds I67.2; it is not part of this code and both may be reported when both are documented.

  Full comparison: I70.661 vs I67.2 →

• K55.1— Excludes2 relationship (Informational)

  Distinct conditions — both may be reported.

  A distinct condition — both may be reported when both are documented.

  What moves you there: Documentation of mesenteric atherosclerosis adds K55.1; it is not part of this code and both may be reported when both are documented.

  Full comparison: I70.661 vs K55.1 →

Relationships are read from this code's own official notes, its laterality siblings and its encounter family; the wording of each distinction is MedCoder editorial, and the documentation named in each “what moves you there” line is the official note phrase or sibling title itself. Source: CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a.

Decision Points

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

1. Laterality is coded in this family. Confirm the documented side matches the code — the opposite-side siblings are in the relationships section. See the opposite-side sibling codes
2. 8 Use Additional Code instructions — report the named additional code(s) when the documentation supports them. See the Use Additional Code notes
3. 8 Excludes2 entries — those conditions are not part of this code and may be reported additionally when documented. See the Excludes2 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

• Age-restricted: the Medicare Code Editor lists this as an adult (age 15-124) diagnosis; other ages are presumed incorrect.
• 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 I70.661 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: I77.6 — Arteritis, unspecified (via I70.-).

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

Referenced by 1 Code First instruction: I70.92 — Chronic total occlusion of artery of the extremities (via I70.6.-).

Each of these codes carries a Code First note naming this condition — when that code is reported, THIS code is sequenced first, ahead of it.

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 46 clinically related codes on its CMS exclusion list.

Named in the grouper logic of 3 MS-DRGs: DRG 299 (MDC 05), DRG 300 (MDC 05), DRG 301 (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):CIR026 — Peripheral and visceral vascular disease (default); CIR028 — Gangrene.

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.

G89.22 — Chronic post-thoracotomy pain, G89.28 — Other chronic postprocedural pain, G89.29 — Other chronic pain, G89.3 — Neoplasm related pain (acute) (chronic), G89.4 — Chronic pain syndrome, I70.261 — Atherosclerosis of native arteries of extremities with gangrene, right leg, I70.262 — Atherosclerosis of native arteries of extremities with gangrene, left leg, I70.263 — Atherosclerosis of native arteries of extremities with gangrene, bilateral legs, I70.268 — Atherosclerosis of native arteries of extremities with gangrene, other extremity, I70.269 — Atherosclerosis of native arteries of extremities with gangrene, unspecified extremity, I96 — Gangrene, not elsewhere classified, R41.0 — Disorientation, unspecified, R41.1 — Anterograde amnesia, R41.2 — Retrograde amnesia, R41.3 — Other amnesia, R41.82 — Altered mental status, unspecified, R41.9 — Unspecified symptoms and signs involving cognitive functions and awareness, R44.8 — Other symptoms and signs involving general sensations and perceptions, R44.9 — Unspecified symptoms and signs involving general sensations and perceptions, R45.83 — Excessive crying of child, adolescent or adult, +25 more

Same condition, opposite side

Same category and title, differing only in which side of the body is affected.

I70.662 — Atherosclerosis of nonbiological bypass graft(s) of the extremities with gangrene, left legCompare I70.661 vs I70.662 →

Same CMS-HCC risk category (V28)

CMS maps these diagnoses to the same Hierarchical Condition Category (Atherosclerosis of Arteries of the Extremities with Ulceration or Gangrene) for risk-adjusted payment.

I70.638 — Atherosclerosis of nonbiological bypass graft(s) of the right leg with ulceration of other part of lower leg, I70.639 — Atherosclerosis of nonbiological bypass graft(s) of the right leg with ulceration of unspecified site, I70.641 — Atherosclerosis of nonbiological bypass graft(s) of the left leg with ulceration of thigh, I70.642 — Atherosclerosis of nonbiological bypass graft(s) of the left leg with ulceration of calf, I70.643 — Atherosclerosis of nonbiological bypass graft(s) of the left leg with ulceration of ankle, I70.644 — Atherosclerosis of nonbiological bypass graft(s) of the left leg with ulceration of heel and midfoot, I70.645 — Atherosclerosis of nonbiological bypass graft(s) of the left leg with ulceration of other part of foot, I70.648 — Atherosclerosis of nonbiological bypass graft(s) of the left leg with ulceration of other part of lower leg, I70.649 — Atherosclerosis of nonbiological bypass graft(s) of the left leg with ulceration of unspecified site, I70.65 — Atherosclerosis of nonbiological bypass graft(s) of other extremity with ulceration, I70.662 — Atherosclerosis of nonbiological bypass graft(s) of the extremities with gangrene, left leg, I70.663 — Atherosclerosis of nonbiological bypass graft(s) of the extremities with gangrene, bilateral legs, I70.668 — Atherosclerosis of nonbiological bypass graft(s) of the extremities with gangrene, other extremity, I70.669 — Atherosclerosis of nonbiological bypass graft(s) of the extremities with gangrene, unspecified extremity, I70.731 — Atherosclerosis of other type of bypass graft(s) of the right leg with ulceration of thigh, I70.732 — Atherosclerosis of other type of bypass graft(s) of the right leg with ulceration of calf, I70.733 — Atherosclerosis of other type of bypass graft(s) of the right leg with ulceration of ankle, I70.734 — Atherosclerosis of other type of bypass graft(s) of the right leg with ulceration of heel and midfoot, I70.735 — Atherosclerosis of other type of bypass graft(s) of the right leg with ulceration of other part of foot, I70.738 — Atherosclerosis of other type of bypass graft(s) of the right leg with ulceration of other part of lower leg, +106 more

Related risk categories

These categories interact through CMS's HCC hierarchy — one can suppress the other's risk-adjustment weight when both are present on a claim.

Vascular Disease with Complications, Chronic Ulcer of Skin, Except Pressure, Not Specified as Through to Bone or Muscle, Amputation Status, Lower Limb/Amputation Complications

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical categories (Peripheral and visceral vascular disease, Gangrene).

I70.638 — Atherosclerosis of nonbiological bypass graft(s) of the right leg with ulceration of other part of lower leg, I70.639 — Atherosclerosis of nonbiological bypass graft(s) of the right leg with ulceration of unspecified site, I70.641 — Atherosclerosis of nonbiological bypass graft(s) of the left leg with ulceration of thigh, I70.642 — Atherosclerosis of nonbiological bypass graft(s) of the left leg with ulceration of calf, I70.643 — Atherosclerosis of nonbiological bypass graft(s) of the left leg with ulceration of ankle, I70.644 — Atherosclerosis of nonbiological bypass graft(s) of the left leg with ulceration of heel and midfoot, I70.645 — Atherosclerosis of nonbiological bypass graft(s) of the left leg with ulceration of other part of foot, I70.648 — Atherosclerosis of nonbiological bypass graft(s) of the left leg with ulceration of other part of lower leg, I70.649 — Atherosclerosis of nonbiological bypass graft(s) of the left leg with ulceration of unspecified site, I70.65 — Atherosclerosis of nonbiological bypass graft(s) of other extremity with ulceration, I70.662 — Atherosclerosis of nonbiological bypass graft(s) of the extremities with gangrene, left leg, I70.663 — Atherosclerosis of nonbiological bypass graft(s) of the extremities with gangrene, bilateral legs, I70.668 — Atherosclerosis of nonbiological bypass graft(s) of the extremities with gangrene, other extremity, I70.669 — Atherosclerosis of nonbiological bypass graft(s) of the extremities with gangrene, unspecified extremity, I70.691 — Other atherosclerosis of nonbiological bypass graft(s) of the extremities, right leg, I70.692 — Other atherosclerosis of nonbiological bypass graft(s) of the extremities, left leg, I70.693 — Other atherosclerosis of nonbiological bypass graft(s) of the extremities, bilateral legs, I70.698 — Other atherosclerosis of nonbiological bypass graft(s) of the extremities, other extremity, I70.699 — Other atherosclerosis of nonbiological bypass graft(s) of the extremities, unspecified extremity, I70.701 — Unspecified atherosclerosis of other type of bypass graft(s) of the extremities, right leg, +279 more

Same Index main term, other category

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

I25.760 — Atherosclerosis of bypass graft of coronary artery of transplanted heart with unstable angina (coronary, transplanted heart, bypass graft, with, angina pectoris, unstable), I25.761 — Atherosclerosis of bypass graft of coronary artery of transplanted heart with angina pectoris with documented spasm (coronary, transplanted heart, bypass graft, with, angina pectoris, with documented spasm), I25.762 — Atherosclerosis of bypass graft of coronary artery of transplanted heart with refractory angina pectoris (coronary, transplanted heart, bypass graft, with, angina pectoris, refractory), I25.768 — Atherosclerosis of bypass graft of coronary artery of transplanted heart with other forms of angina pectoris (coronary, transplanted heart, bypass graft, with, angina pectoris, specified type), I25.769 — Atherosclerosis of bypass graft of coronary artery of transplanted heart with unspecified angina pectoris (coronary, transplanted heart, bypass graft, with, angina pectoris), I25.790 — Atherosclerosis of other coronary artery bypass graft(s) with unstable angina pectoris (coronary, bypass graft, specified type NEC, with, angina pectoris, unstable), I25.791 — Atherosclerosis of other coronary artery bypass graft(s) with angina pectoris with documented spasm (coronary, bypass graft, specified type NEC, with, angina pectoris, with documented spasm), I25.792 — Atherosclerosis of other coronary artery bypass graft(s) with refractory angina pectoris (coronary, bypass graft, specified type NEC, with, angina pectoris, refractory), I25.798 — Atherosclerosis of other coronary artery bypass graft(s) with other forms of angina pectoris (coronary, bypass graft, specified type NEC, with, angina pectoris, specified type), I25.799 — Atherosclerosis of other coronary artery bypass graft(s) with unspecified angina pectoris (coronary, bypass graft, specified type NEC, with, angina pectoris), I25.810 — Atherosclerosis of coronary artery bypass graft(s) without angina pectoris (coronary, bypass graft), I25.811 — Atherosclerosis of native coronary artery of transplanted heart without angina pectoris (coronary, transplanted heart), I25.812 — Atherosclerosis of bypass graft of coronary artery of transplanted heart without angina pectoris (coronary, transplanted heart, bypass graft), I25.83 — Coronary atherosclerosis due to lipid rich plaque (coronary, due to, lipid rich plaque), I25.84 — Coronary atherosclerosis due to calcified coronary lesion (coronary, due to, calcified coronary lesion), I27.0 — Primary pulmonary hypertension (pulmonary), I51.4 — Myocarditis, unspecified (myocarditis), I65.2 — Occlusion and stenosis of carotid artery (carotid), I67.2 — Cerebral atherosclerosis (brain), K55.1 — Chronic vascular disorders of intestine (mesenteric), +32 more

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.

Blood Glucose Test, Lipid Panel, Partial Thromboplastin Time (PTT) Test, Prothrombin Time Test and INR (PT/INR)

Contextual Map

Every relationship of I70.661 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 I70.661 with these 2 related codes in Claim Check

Hierarchy

• I00-I99 — Chapter 9: Diseases of the Circulatory System (I00-I99) (I00-I99)[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• I70-I79 — Diseases of arteries, arterioles and capillaries[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026

Referenced by Excludes1 notes

• I77.6 — Arteritis, unspecified[Excludes1](via I70.-): “deformans (I70.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Referenced by Code First instructions

• I70.92 — Chronic total occlusion of artery of the extremities[Code First](via I70.6.-): “atherosclerosis of arteries of the extremities (I70.2-, I70.3-, I70.4-, I70.5-, I70.6-, I70.7-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Clinical classification (CCSR)

• CIR026 — Peripheral and visceral vascular disease[CCSR]— AHRQ CCSR for ICD-10-CM Diagnoses (HCUP)
• CIR028 — Gangrene[CCSR]— AHRQ CCSR for ICD-10-CM Diagnoses (HCUP)

Risk adjustment (CMS-HCC)

• HCC 263 — Atherosclerosis of Arteries of the Extremities with Ulceration or Gangrene [CMS-HCC]: “Atherosclerosis of Arteries of the Extremities with Ulceration or Gangrene — supersedes HCC 264 (Vascular Disease with Complications), HCC 383 (Chronic Ulcer of Skin, Except Pressure, Not Specified as Through to Bone or Muscle), HCC 409 (Amputation Status, Lower Limb/Amputation Complications)”— CMS-HCC V28 · 2026

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 299 — PERIPHERAL VASCULAR DISORDERS WITH MCC[MS-DRG]: “PERIPHERAL VASCULAR DISORDERS WITH MCC (MDC 05)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
• DRG 300 — PERIPHERAL VASCULAR DISORDERS WITH CC[MS-DRG]: “PERIPHERAL VASCULAR DISORDERS WITH CC (MDC 05)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
• DRG 301 — PERIPHERAL VASCULAR DISORDERS WITHOUT CC/MCC[MS-DRG]: “PERIPHERAL VASCULAR DISORDERS WITHOUT CC/MCC (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

• Arteriosclerosis, arteriosclerotic (diffuse) (obliterans) (of) (senile) (with calcification), extremities (native arteries), bypass graft, nonbiological graft, leg, right, with, gangrene (and intermittent claudication, rest pain and ulcer)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
• Arteriosclerosis, arteriosclerotic (diffuse) (obliterans) (of) (senile) (with calcification), with, critical limb ischemia, bypass graft, nonbiological graft, leg, right, with, gangrene (and intermittent claudication, rest pain, and ulcer)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026

Nearest codes (40)

• I70 — Atherosclerosis[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• I70.628 — Atherosclerosis of nonbiological bypass graft(s) of the extremities with rest pain, other extremity[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• I70.629 — Atherosclerosis of nonbiological bypass graft(s) of the extremities with rest pain, unspecified extremity[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• I70.63 — Atherosclerosis of nonbiological bypass graft(s) of the right leg with ulceration[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• I70.631 — Atherosclerosis of nonbiological bypass graft(s) of the right leg with ulceration of thigh[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• I70.632 — Atherosclerosis of nonbiological bypass graft(s) of the right leg with ulceration of calf[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• I70.633 — Atherosclerosis of nonbiological bypass graft(s) of the right leg with ulceration of ankle[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• I70.634 — Atherosclerosis of nonbiological bypass graft(s) of the right leg with ulceration of heel and midfoot[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• and 32 more

Change history

• FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

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

Risk adjustment Official source data

2026 Mid-Year Final ICD-10 Mappings + Model Software (cms.gov/files/zip/2026-midyear-final-icd-10-mappings.zip, 2026-midyear-final-model-software.zip) — CMS-HCC V28, PY2026 mid-year final release 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

Nearest Codes in This Family

Official ICD-10-CM classifications closest to I70.661 in its code family, with their registry titles.

• I70.645 — Atherosclerosis of nonbiological bypass graft(s) of the left leg with ulceration of other part of foot
• I70.648 — Atherosclerosis of nonbiological bypass graft(s) of the left leg with ulceration of other part of lower leg
• I70.649 — Atherosclerosis of nonbiological bypass graft(s) of the left leg with ulceration of unspecified site
• I70.65 — Atherosclerosis of nonbiological bypass graft(s) of other extremity with ulceration
• I70.66 — Atherosclerosis of nonbiological bypass graft(s) of the extremities with gangrene
• I70.662 — Atherosclerosis of nonbiological bypass graft(s) of the extremities with gangrene, left leg
• I70.663 — Atherosclerosis of nonbiological bypass graft(s) of the extremities with gangrene, bilateral legs
• I70.668 — Atherosclerosis of nonbiological bypass graft(s) of the extremities with gangrene, other extremity
• I70.669 — Atherosclerosis of nonbiological bypass graft(s) of the extremities with gangrene, unspecified extremity
• I70.69 — Other atherosclerosis of nonbiological bypass graft(s) of the extremities

View all codes in the I70 family