M31.4 — Aortic arch syndrome [Takayasu]
M31.4 is a billable, specific ICD-10-CM code for aortic arch syndrome [takayasu]. It is valid for submission on a claim.
Other codes that can never be billed with M31.4
These codes carry an Excludes1 note pointing at M31.4. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading M31.4 alone.
- I77.6Arteritis, unspecified
Risk adjustment
M31.4 risk-adjusts. Under the CMS-HCC V28 model it maps to this category:
- HCC 93 Rheumatoid Arthritis and Other Specified Inflammatory Rheumatic Disorders0.617 RAF
Coefficient shown for the Community Non-dual Aged segment. A higher HCC in the same hierarchy will suppress this one, so capturing it does not always add score.
Medicare coverage
M31.4 is named in 26 Medicare coverage policies — 20 listing it as supporting medical necessity, and 6 listing it as NOT covered. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.
- A58865Billing and Coding: Amniotic and Placental-Derived Product Injections and/or Applications for Musculoskeletal Indications, Non-Woundnot covered
- A58893Billing and Coding: Amniotic and Placental-Derived Product Injections and/or Applications for Musculoskeletal Indications, Non-Woundnot covered
- A59374Billing and Coding: Amniotic and Placental-Derived Product Injections and/or Applications for Musculoskeletal Indications, Non-Woundnot covered
- A59434Billing and Coding: Amniotic and Placental-Derived Product Injections and/or Applications for Musculoskeletal Indications, Non-Woundnot covered
How M31.4 is indexed
Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to M31.4.
- Takayasu's disease or syndrome
- Arteritis›aortic arch
- Arteritis›brachiocephalic
- Arteritis›young female aortic arch syndrome
- Disease, diseased›pulseless
- Syndrome›aortic›arch
Related codes at this level
Codes that share M31. If M31.4 is not quite right, the correct code is usually one of these.
- M31.0Hypersensitivity angiitis
- M31.1Thrombotic microangiopathy
- M31.2Lethal midline granuloma
- M31.3Wegener's granulomatosis
- M31.5Giant cell arteritis with polymyalgia rheumatica
- M31.6Other giant cell arteritis
- M31.7Microscopic polyangiitis
- M31.8Other specified necrotizing vasculopathies
- M31.9Necrotizing vasculopathy, unspecified
Questions about M31.4
- Is M31.4 a billable ICD-10-CM code?
- Yes. M31.4 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
- Where does M31.4 sit in the tabular list?
- Diseases of the musculoskeletal system and connective tissue (M00-M99), in the block Systemic connective tissue disorders (M30-M36).