What is the ICD-10 code for ankylosing spondylitis?

The ICD-10 code for ankylosing spondylitis is M45, used when X-ray shows sacroiliitis.

How is non-radiographic axial spondyloarthritis coded?

Non-radiographic axial spondyloarthritis is coded as M46.8 when MRI shows inflammation but X-ray is negative.

ICD-10 Coding for Spondyloarthropathy(M45, M46.8, L40.5)

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Explore detailed ICD-10 coding for spondyloarthropathy, including ankylosing spondylitis and non-radiographic axial spondyloarthritis. Learn about documentation requirements and coding pitfalls.

Also known as:

Axial SpondyloarthritisAnkylosing SpondylitisNon-radiographic Axial Spondyloarthritis

Related ICD-10 Code Ranges

Complete code families applicable to Spondyloarthropathy

M00-M99Primary Range

Diseases of the musculoskeletal system and connective tissue

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Code Comparison: When to Use Each Code

Compare key differences between these codes to ensure accurate selection

Code	Description	When to Use	Key Documentation
M45	Ankylosing spondylitis	Use when X-ray shows sacroiliitis and patient meets clinical criteria for ankylosing spondylitis.	Bilateral grade ≥2 sacroiliitis on X-ray HLA-B27 positive Morning stiffness >30 mins
M46.8	Non-radiographic axial spondyloarthritis	Use when MRI shows inflammation and clinical criteria for axial spondyloarthritis are met, but X-ray is negative.	Active sacroiliitis on MRI IBP ≥3 months Negative X-ray + 1 more
M46.1	Peripheral spondyloarthritis	Use when peripheral manifestations such as dactylitis or enthesitis are present.	Dactylitis (sausage digit) Enthesitis (Achilles/plantar fascia) Psoriasis

Primary ICD-10-CM Codes

Ankylosing spondylitis

M45

Other specified inflammatory spondylopathies

M46.8

Differential Codes

Alternative codes to consider when ruling out similar conditions

Non-radiographic axial spondyloarthritisM46.8

Ankylosing spondylitisM45

Psoriatic arthritisL40.5

Documentation & Coding Risks

Avoid these common issues when documenting Spondyloarthropathy.

Failure to document HLA-B27 status

Impact

Clinical: May lead to incorrect diagnosis and treatment., Regulatory: Non-compliance with documentation standards., Financial: Potential denial of claims due to incomplete documentation.

Mitigation

Ensure HLA-B27 testing is ordered and results documented., Include HLA-B27 status in the assessment section.

Using M46.9 for unspecified spondyloarthropathy

Impact

Reimbursement: May lead to lower reimbursement due to lack of specificity., Compliance: Non-compliance with coding guidelines for specificity., Data Quality: Reduces data quality and accuracy in patient records.

Mitigation

Specify the type of spondyloarthropathy using M45 or M46.8 based on clinical findings.

Specificity of Diagnosis

Impact

Risk of audits due to use of unspecified codes.

Mitigation

Ensure detailed documentation of clinical findings and imaging results.

Frequently Asked Questions

Documentation requirements, coding pitfalls and FAQs for conditions coded with M45.

Primary Code

M45

Ankylosing spondylitis

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ICD-10 codes7

Coding risks3

FAQs2

ICD-10 Coding for Spondyloarthropathy(M45, M46.8, L40.5)

Documentation & Coding Risks

Frequently Asked Questions

What is the ICD-10 code for ankylosing spondylitis?

How is non-radiographic axial spondyloarthritis coded?

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