U.S. ICD-10-CM · FY 2027

M45 ICD-10-CM Code: Ankylosing spondylitis

A clear reference for the official code description, hierarchy, and related coding information from the FY 2027 U.S. release.

Code definition

Official description

M45

Ankylosing spondylitis

ICD-10-CM diagnosis code · United States clinical modification

Classification

Where M45 sits

  1. 1

    Chapter 13

    Diseases of the musculoskeletal system and connective tissue (M00-M99)

  2. 2

    Section

    Spondylopathies (M45-M49)

  3. 3

    Category M45

    Ankylosing spondylitis

  4. 4

    Code M45

    Ankylosing spondylitis

More specific choices

Codes under M45

M45 is a non-billable category. Choose the child code that best matches the documented diagnosis.

M45.0

Ankylosing spondylitis of multiple sites in spine

M45.1

Ankylosing spondylitis of occipito-atlanto-axial region

M45.2

Ankylosing spondylitis of cervical region

M45.3

Ankylosing spondylitis of cervicothoracic region

M45.4

Ankylosing spondylitis of thoracic region

M45.5

Ankylosing spondylitis of thoracolumbar region

M45.6

Ankylosing spondylitis lumbar region

M45.7

Ankylosing spondylitis of lumbosacral region

M45.8

Ankylosing spondylitis sacral and sacrococcygeal region

M45.9

Ankylosing spondylitis of unspecified sites in spine

M45.A

Non-radiographic axial spondyloarthritis

Documentation details

Notes for this code

Inclusion terms

  • Rheumatoid arthritis of spine

Code first

No “code first” instruction is listed for M45.

Use additional code

No “use additional code” instruction is listed for M45.

Excludes1

Conditions that should not be reported together with this code.

  • arthropathy in Reiter's disease (M02.3-)
  • juvenile (ankylosing) spondylitis (M08.1)

Excludes2

Conditions not included here that may be reported separately when present.

  • Behçet's disease (M35.2)

Transparency

Source and release

Data release

U.S. ICD-10-CM · FY 2027

Effective date

Oct 1, 2026

Publisher

Vero Scribe Inc.

This reference is generated from Vero’s ICD-10-CM description, hierarchy, and code-note dataset. The visible content and structured data share that source.

Review the CDC/NCHS ICD-10-CM source

Code-specific guidance

Frequently asked questions

What does ICD-10-CM code M45 mean?

M45 is the FY 2027 U.S. ICD-10-CM code for “Ankylosing spondylitis.”

Is M45 a billable or specific ICD-10-CM code?

No. M45 has more specific child codes in the FY 2027 reference data. Select the code that matches the documentation and confirm the active code set and payer requirements.

Where is M45 located in ICD-10-CM?

M45 is listed in Chapter 13, Diseases of the musculoskeletal system and connective tissue (M00-M99), within Spondylopathies (M45-M49) (M45–M49), under category M45, Ankylosing spondylitis.

What coding notes are listed for M45?

Its listed inclusion terms are Rheumatoid arthritis of spine. No code-first instruction is listed. Excludes1 notes: arthropathy in Reiter's disease (M02.3-); juvenile (ankylosing) spondylitis (M08.1). Excludes2 notes: Behçet's disease (M35.2).

Ready to transform your clinical documentation?

Join Vero and see how effortless documentation can be.

Try for free

  • No credit card required

  • Cancel anytime