M43.01 Spondylolysis, occipito-atlanto-axial region

Billable ICD-10-CM code, FY2026.

Applies from M43 Other deforming dorsopathies

Excludes1 (never code together)

• congenital spondylolysis and spondylolisthesis (Q76.2)
• hemivertebra (Q76.3-Q76.4)
• Klippel-Feil syndrome (Q76.1)
• lumbarization and sacralization (Q76.4)
• platyspondylisis (Q76.4)
• spina bifida occulta (Q76.0)
• spinal curvature in osteoporosis (M80.-)
• spinal curvature in Paget's disease of bone [osteitis deformans] (M88.-)

Applies from M43.0 Spondylolysis

Excludes1 (never code together)

• congenital spondylolysis (Q76.2)
• spondylolisthesis (M43.1)

MS-DRG index

Defines the logic of DRG(s) 551-552 in MDC 08.

Approximate ICD-9-CM (GEMs)

• 738.4 Acquired spondylolisthesis (approximate)

Code annotations containing back-references to M43.01

Back-references to M43.0

• Type 1 Excludes: Q76.2 Congenital spondylolisthesis ("spondylolysis (acquired) (M43.0-)")

Back-references to M43

• Type 2 Excludes: M95 Other acquired deformities of musculoskeletal system and connective tissue ("deforming dorsopathies (M40-M43)")

Diagnosis Index entries for M43.01

• Spondylolysis (acquired) › occipito-atlanto-axial region

Nearby codes

• M43 Other deforming dorsopathies
• M43.0 Spondylolysis
• M43.00 Spondylolysis, site unspecified
• M43.01 Spondylolysis, occipito-atlanto-axial region (this code)
• M43.02 Spondylolysis, cervical region
• M43.03 Spondylolysis, cervicothoracic region
• M43.04 Spondylolysis, thoracic region
• M43.05 Spondylolysis, thoracolumbar region
• M43.06 Spondylolysis, lumbar region