Skip to main content

I70.221 vs I70.229

I70.221 (Atherosclerosis of native arteries of extremities with rest pain, right leg) compared with I70.229 (Atherosclerosis of native arteries of extremities with rest pain, unspecified extremity), from the official CMS tabular data.

Summary

These codes represent different levels of specificity within category I70: I70.221 is the more specific code and I70.229 is the unspecified one.

MedCoder-derived
What is different?

Title wording.The titles share “Atherosclerosis of native arteries of extremities with rest pain”; I70.221 says “right leg” where I70.229 says “unspecified extremity”.

Registry fact

Can these codes be reported together?

Not ordinarily.I70.221 is the more specific code and I70.229 is the unspecified one, in the same category. When the documentation supports the more specific code, the unspecified code is not added for the same condition (ICD-10-CM Official Guidelines, Section I.B.18).

MedCoder-derivedGuide: Other vs unspecified (NEC vs NOS)

Is there an Excludes1 relationship?

None.Neither entry carries an Excludes1 note that names the other code.

Official rule

Is there an Excludes2 relationship?

None.Neither entry carries an Excludes2 note that names the other code. I70.221 carries 9 Excludes2 notes and I70.229 carries 9 Excludes2 notes covering other codes; the side-by-side table quotes them.

Official rule

Is one more specific?

Yes.I70.221’s title names the condition; I70.229’s title is the unspecified form (“Atherosclerosis of native arteries of extremities with rest pain, unspecified extremity”).

MedCoder-derivedGuide: Other vs unspecified (NEC vs NOS)

Is one a parent or header code?

No.Both are billable codes, and neither contains the other.

Registry fact

Are there sequencing instructions?

None.Neither entry carries a Code First or Use Additional Code note that names the other.

Official rule

Are there other coding relationships?

None found.No laterality, encounter-phase, Table of Neoplasms, Table of Drugs and Chemicals, or history-versus-active-disease relationship links these codes.

MedCoder-derived

Official rule: a tabular instructional note or a section of the ICD-10-CM Official Guidelines, quoted as published. Registry fact: the codes’ own published attributes (titles, billable status, position in the hierarchy, code set). MedCoder-derived: a reading MedCoder computes from those facts; it is not itself a rule. How to read the labels

Can these codes be reported together?

Review

Specificity relationship

I70.229
Atherosclerosis of native arteries of extremities with rest pain, unspecified extremity
I70.221
Atherosclerosis of native arteries of extremities with rest pain, right leg

What we found

Not ordinarily reported together for the same condition. No Excludes1/Excludes2 relationship is listed between I70.229 and I70.221, but they describe overlapping diagnoses in the same category (Both are children of the same I70 category.).

When documentation supports the more specific code, the unspecified code should generally not be added for the same condition (ICD-10-CM Official Guidelines, Section I.B.18).

What to review

When the documentation supports the more specific code, report it and leave the unspecified code off for the same condition.

Guide: Other vs unspecified (NEC vs NOS)Check these on a claim

Why it matters

No Excludes note links these codes, but they describe overlapping diagnoses and one of them is unspecified. When documentation supports the more specific code, the unspecified code should generally not be added for the same condition.

Source / rule

ICD-10-CM Official Guidelines, Section I.B.18

Official guidance behind these answers

  • Section I.B.18 — Use of Sign/Symptom/Unspecified Codes · applies to: Unspecified codes

    Sign/symptom and “unspecified” codes have acceptable, even necessary, uses. While specific diagnosis codes should be reported when they are supported by the available medical record documentation and clinical knowledge of the patient’s health condition, there are instances when signs/symptoms or unspecified codes are the best choices for accurately reflecting the healthcare encounter. Each healthcare encounter should be coded to the level of certainty known for that encounter. As stated in the introductory section of these official coding guidelines, a joint effort between the healthcare provider and the coder is essential to achieve complete and accurate documentation, code assignment, and reporting of diagnoses and procedures. The importance of consistent, complete documentation in the medical record cannot be overemphasized. Without such documentation accurate coding cannot be achieved. The entire record should be reviewed to determine the specific reason for the encounter and the conditions treated. If a definitive diagnosis has not been established by the end of the encounter, it is appropriate to report codes for sign(s) and/or symptom(s) in lieu of a definitive diagnosis. When sufficient clinical information isn’t known or available about a particular health condition to assign a more specific code, it is acceptable to report the appropriate “unspecified” code (e.g., a diagnosis of pneumonia has been determined, but not the specific type). […]

    ICD-10-CM Official Guidelines FY2026

  • Section I.B.2 — Level of Detail in Coding · applies to: Level of detail

    Diagnosis codes are to be used and reported at their highest number of characters available and to the highest level of specificity documented in the medical record. ICD-10-CM diagnosis codes are composed of codes with 3, 4, 5, 6 or 7 characters. Codes with three characters are included in ICD-10-CM as the heading of a category of codes that may be further subdivided by the use of fourth and/or fifth characters and/or sixth characters, which provide greater detail. A three-character code is to be used only if it is not further subdivided. A code is invalid if it has not been coded to the full number of characters required for that code, including the 7th character, if applicable.

    ICD-10-CM Official Guidelines FY2026

Quoted from the ICD-10-CM Official Guidelines for Coding and Reporting in effect for the release shown. The tabular notes above are the code-level instruction; these sections are the convention that says how such a note is applied. Source document (CMS PDF) · Release and checksum

Side by side

I70.221Atherosclerosis of native arteries of extremities with rest pain, right legI70.229Atherosclerosis of native arteries of extremities with rest pain, unspecified extremity
Billing statusBillableBillable
ClassificationI00-I99 — Diseases of the Circulatory System (I00-I99)I00-I99 — Diseases of the Circulatory System (I00-I99)
DefinitionAtherosclerosis of native arteries of extremities with rest pain, right leg is a billable ICD-10-CM diagnosis code (I70.221).Atherosclerosis of native arteries of extremities with rest pain, unspecified extremity is a billable ICD-10-CM diagnosis code (I70.229).
Includes
any condition classifiable to I70.21-
chronic limb-threatening ischemia NOS of native arteries of extremities
chronic limb-threatening ischemia of native arteries of extremities with rest pain
critical limb ischemia NOS of native arteries of extremities
any condition classifiable to I70.21-
chronic limb-threatening ischemia NOS of native arteries of extremities
chronic limb-threatening ischemia of native arteries of extremities with rest pain
critical limb ischemia NOS of native arteries of extremities
Excludes2
atherosclerosis of bypass graft of extremities (I70.30-I70.79)
arteriosclerotic cardiovascular disease (I25.1-)
arteriosclerotic heart disease (I25.1-)
atheroembolism (I75.-)
cerebral atherosclerosis (I67.2)
coronary atherosclerosis (I25.1-)
mesenteric atherosclerosis (K55.1)
precerebral atherosclerosis (I67.2)
primary pulmonary atherosclerosis (I27.0)
atherosclerosis of bypass graft of extremities (I70.30-I70.79)
arteriosclerotic cardiovascular disease (I25.1-)
arteriosclerotic heart disease (I25.1-)
atheroembolism (I75.-)
cerebral atherosclerosis (I67.2)
coronary atherosclerosis (I25.1-)
mesenteric atherosclerosis (K55.1)
precerebral atherosclerosis (I67.2)
primary pulmonary atherosclerosis (I27.0)
Use additional code
code, if applicable, to identify chronic total occlusion of artery of extremity (I70.92)
code to identify:
exposure to environmental tobacco smoke (Z77.22)
code, if applicable, to identify chronic total occlusion of artery of extremity (I70.92)
code to identify:
exposure to environmental tobacco smoke (Z77.22)

Notes are the code’s own tabular entry, quoted as published. A note that names the other code is the one the verdict above rests on.

Derived from the official CMS ICD-10-CM tabular data (FY2027). A coding-rule comparison, not billing advice: payer-specific edits and medical-necessity policy are outside its scope. All data sources