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ICD-10-CM 2027

ICD-10 code for axillary adenitis

I88.9

Nonspecific lymphadenitis, unspecified

✓ Billable / specific

From the official ICD-10-CM alphabetic index entry “Adenitis › axillary”. Page updated September 29, 2026.

About coding axillary adenitis

The ICD-10-CM code for axillary adenitis is I88.9 (Nonspecific lymphadenitis, unspecified). The official index lists 2 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on I88.9.

Within I88, choose I88.9 (unspecified) only when documentation doesn't support a more specific option: nonspecific mesenteric lymphadenitis (I88.0), chronic lymphadenitis, except mesenteric (I88.1) and other nonspecific lymphadenitis (I88.8).

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 814 (Reticuloendothelial and Immunity Disorders with MCC, relative weight 2.0729), DRG 815 (Reticuloendothelial and Immunity Disorders with CC, relative weight 1.0444) and DRG 816 (Reticuloendothelial and Immunity Disorders without CC/MCC, relative weight 0.7381), in MDC 16 (Diseases and Disorders of the Blood and Blood Forming Organs and Immunological Disorders), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

More specific axillary adenitis codes (official index)

  • acute L04.2 — Acute lymphadenitis of upper limb
  • chronic or subacute I88.1 — Chronic lymphadenitis, except mesenteric

Common questions about axillary adenitis ICD-10 codes

What is the ICD-10 code for axillary adenitis?

I88.9 — Nonspecific lymphadenitis, unspecified. More specific codes apply when the documentation supports them: L04.2, I88.1.

What is the ICD-10 code for acute axillary adenitis?

L04.2 — Acute lymphadenitis of upper limb.

What is the ICD-10 code for chronic or subacute axillary adenitis?

I88.1 — Chronic lymphadenitis, except mesenteric.

Is I88.9 billable?

Yes. I88.9 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can I88.9 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict I88.9 as a principal diagnosis.

Is I88.9 a CC or MCC?

No. I88.9 is neither a CC nor an MCC under MS-DRG v44.0.