Skip to main content
Call AIBook a demo

ICD-10-CM I70.638: Atherosclerosis of nonbiological bypass graft(s) of the right leg with ulceration of other part of lower leg

I70.638 is the billable ICD-10-CM code for atherosclerosis of nonbiological bypass graft(s) of the right leg with ulceration of other part of lower leg, in category I70 (Atherosclerosis) of the Diseases of arteries, arterioles and capillaries section. As a principal diagnosis it groups to MS-DRG 299 Peripheral Vascular Disorders with MCC, MS-DRG 300 Peripheral Vascular Disorders with CC, MS-DRG 301 Peripheral Vascular Disorders without CC/MCC (MDC 05 MDC 05: Diseases and Disorders of the Circulatory System). It maps to HCC 263 (Atherosclerosis of Arteries of the Extremities with Ulceration or Gangrene) and HCC 383 (Chronic Ulcer of Skin, Except Pressure, Not Specified as Through to Bone or Muscle) in CMS-HCC V28. As a secondary diagnosis it is a CC, excluded with 326 principal diagnoses. 21 LCD billing and coding articles list it as covered.

Compiled from CMS files by the QuickIntell RCM Editorial Team · Data effective · Method: reference methodology · Report a data correction

Data currency: ICD-10-CM code descriptions: FY2027 (effective October 1, 2026); IPPS Table 5 (MS-DRG weights): v44 FY2027 (final rule + CN3) (effective October 1, 2026); ICD-10-CM to HCC mapping: PY2027 initial ICD-10-CM mappings (dates of service 2026) (payment year 2027); Medicare Coverage Database billing and coding articles: MCD release October 8, 2026 (effective October 4, 2026). Next CMS release: FY2028 code files, effective October 1, 2027 for the ICD-10-CM code descriptions; FY2028 final rule (August 2027), effective October 1, 2027; an April 1 interim grouper update when CMS issues one for the IPPS Table 5 (MS-DRG weights); PY2028 advance notice (February 2027) and the PY2027 midyear final mapping (spring 2027) for the ICD-10-CM to HCC mapping; weekly, every Thursday for the Medicare Coverage Database billing and coding articles.

Code
I70.638
billable FY2027 ICD-10-CM code
Category
I70 Atherosclerosis
Chapter
9: Diseases of the circulatory system (I00-I99)
CC/MCC (MS-DRG v44)
CC
CMS-HCC V28
HCC 263, HCC 383
POA reporting
Required

Tabular list notes for I70.638

The tabular list has no notes on I70.638 itself; the notes below apply from its parent headings.

Inherited from I70 (Atherosclerosis)

Includes
  • arteriolosclerosis
  • arterial degeneration
  • arteriosclerosis
  • arteriosclerotic vascular disease
  • arteriovascular degeneration
  • atheroma
  • endarteritis deformans or obliterans
  • senile arteritis
  • senile endarteritis
  • vascular degeneration
Excludes2 (not part of this condition, may be coded together)
  • 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 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)

Inherited from I70.6 (Atherosclerosis of nonbiological bypass graft(s) of the extremities)

Use additional code
  • code, if applicable, to identify chronic total occlusion of artery of extremity (I70.92)

Inherited from I70.63 (Atherosclerosis of nonbiological bypass graft(s) of the right leg with ulceration)

Includes
  • any condition classifiable to I70.611 and I70.621
  • chronic limb-threatening ischemia of nonbiological bypass graft(s) of the right leg with ulceration
  • critical limb ischemia of nonbiological bypass graft(s) of the right leg with ulceration
Use additional code
  • code to identify severity of ulcer (L97.-)

MS-DRG grouping when I70.638 is the principal diagnosis

MS-DRG v44 groups for I70.638 as principal diagnosis
MDCMS-DRGs
05 MDC 05: Diseases and Disorders of the Circulatory System299300301

The final group also depends on procedures, secondary diagnoses and discharge status; the MS-DRG lookup for I70.638 shows the full grouping logic.

CC/MCC status and inpatient edits

As a secondary diagnosis, I70.638 is a CC under MS-DRG v44, unless the principal diagnosis is one of the 326 codes in its exclusion list. Check I70.638 against a principal diagnosis.

  • Present on admission: a POA indicator is required on inpatient claims.
  • Medicare Code Editor: age conflict: adult diagnosis (age 15 to 124).

CMS-HCC V28 risk adjustment

In the PY2027 mapping, I70.638 maps to HCC 263 (Atherosclerosis of Arteries of the Extremities with Ulceration or Gangrene), HCC 383 (Chronic Ulcer of Skin, Except Pressure, Not Specified as Through to Bone or Muscle). The HCC lookup shows the RAF weight and the hierarchy.

LCD billing and coding articles that list I70.638

21 current Medicare billing and coding articles list I70.638 among the diagnoses that support medical necessity for the services they cover.

For teams evaluating QuickIntell software

Evaluate software for diagnosis coding review

If your team codes diagnoses at volume, review how QuickCode supports qualified coder review of documentation, specificity queries and the billing handoff. Confirm the code sets, settings and reviewer responsibilities during evaluation; a code reference is not a coding determination for a patient.

Evaluate QuickCode for diagnosis codingSee risk adjustment review
Book a software demoAsk about a software workflow

Optional software evaluation, not payer support or help with an individual claim. For coverage or payment decisions, use the official sources on this page. Do not include patient information in a demo booking or inquiry.

Frequently asked questions

What does ICD-10-CM I70.638 mean?

I70.638 means atherosclerosis of nonbiological bypass graft(s) of the right leg with ulceration of other part of lower leg. It is one of 25 billable codes under I70, atherosclerosis.

Which MS-DRG does I70.638 group to?

As the principal diagnosis, I70.638 groups to MS-DRG 299 Peripheral Vascular Disorders with MCC, MS-DRG 300 Peripheral Vascular Disorders with CC, MS-DRG 301 Peripheral Vascular Disorders without CC/MCC (MDC 05 MDC 05: Diseases and Disorders of the Circulatory System) under MS-DRG v44, before procedures and secondary diagnoses are applied.

Does I70.638 map to an HCC?

Yes: HCC 263, Atherosclerosis of Arteries of the Extremities with Ulceration or Gangrene; HCC 383, Chronic Ulcer of Skin, Except Pressure, Not Specified as Through to Bone or Muscle, in the PY2027 CMS-HCC V28 mapping.

Is I70.638 a CC or MCC?

I70.638 is a CC under MS-DRG v44; 326 principal diagnoses exclude it.

Sources

Every figure on this page is taken from the CMS publications below, as released by the Centers for Medicare & Medicaid Services. Projection built 2026-10-10. Verify against the primary file before billing or contracting decisions. The reference methodology explains how each figure is computed from these files.

Disclaimer

The descriptor and notes are reproduced from the FY2027 ICD-10-CM files; MS-DRG, CC/MCC and HCC facts come from the CMS FY2027 and PY2027 tables. Code from the medical record and the ICD-10-CM Official Guidelines. Not legal, clinical or billing advice.

Found a figure that does not match the CMS file? Report a data correction with the CMS file and the value you expected; the request reaches the editorial team through the contact form.