ICD-10-CM · Spine

M42.9

M42.9 classifies spinal osteochondrosis when neither the age category (juvenile vs. adult) nor the spinal region is documented, capturing a disorder of vertebral ossification centers without further specification.

Verified May 8, 2026 · 5 sources ↓

Status: Billable
Chapter: 13
Related CPT: 15
Region: Spine

Drawn from CDCICD10DataAAPC

Documentation tips

What should appear in the chart to support M42.9.

Source · Editorial brief grounded in 5 cited references ↓

Record the patient's age or age category (skeletally immature vs. adult) so you can move to M42.0x (juvenile) or M42.1x (adult) instead of defaulting to M42.9.
Document the specific spinal region affected — cervical, thoracic, thoracolumbar, lumbar, lumbosacral, or sacral — to support a site-specific subcategory under M42.0 or M42.1.
Note imaging findings that distinguish spinal osteochondrosis from degenerative disc disease (e.g., vertebral endplate irregularity, Schmorl nodes, epiphyseal ring changes on MRI or X-ray).
If Scheuermann disease is suspected, document vertebral wedging angle and number of affected levels — this supports the juvenile subcategory and may influence surgical DRG assignment.
Record whether conservative treatment (bracing, PT, NSAIDs) has been trialed, as this affects medical necessity documentation for imaging and procedure reimbursement.

Related CPT procedures

Procedure codes commonly billed with M42.9. Linking the right diagnosis to the right procedure is what establishes medical necessity.

Source · CMS LCDs · AAOS specialty guidance · claims-pattern analysis

72100 $40.42

Radiologic examination of the lumbosacral spine capturing two or three views, used to evaluate the lumbar vertebrae and sacrum for injury, degeneration, or structural abnormality.

72110 $53.44

Radiologic examination of the lumbar spine (lumbosacral) with a minimum of four views, including oblique and/or bending views.

72114 $61.79

Radiologic examination of the lumbosacral spine, complete series with bending (flexion/extension) views — minimum of 6 views total.

72020 $23.71

Single-view radiologic examination of the spine at a specified level.

72040 $39.75

Radiologic examination of the cervical spine capturing two or three views (e.g., AP, lateral, oblique).

72050 $55.11

Radiologic examination of the cervical spine capturing a minimum of four views, used to evaluate alignment, fractures, degeneration, or other structural pathology of the neck.

72070 $33.07

Two-view radiologic examination of the thoracic spine, including AP and lateral projections of the 12 thoracic vertebrae.

72072 $38.75

Radiographs of the thoracic spine with three views, typically a frontal, a lateral, and one added projection such as a swimmer's view.

72074 $44.09

Thoracic spine radiographs with at least four views, adding obliques or other projections to the standard frontal and lateral images.

72080 $35.07

Radiologic examination of the thoracolumbar junction (where the thoracic and lumbar spine meet), requiring a minimum of two views.

77080 $39.41

Dual-energy X-ray absorptiometry measurement of bone mineral density at axial sites such as the hips, pelvis, or lumbar spine.

20610 $68.81

Aspiration and/or injection of a major joint or bursa (shoulder, hip, knee, or subacromial bursa) performed without ultrasound guidance.

62323 $273.22

Single interlaminar epidural or subarachnoid injection at a lumbar or sacral level, performed under fluoroscopic or CT guidance, delivering a steroid, anesthetic, or other non-neurolytic drug.

63030 $898.15

Single-interspace lumbar laminotomy with nerve root decompression, including partial facetectomy, foraminotomy, and/or herniated disc excision performed via open surgical technique.

63047 $1,065.49

Lumbar laminectomy at a single vertebral segment that also includes facetectomy and foraminotomy for decompression of the spinal cord, cauda equina, and/or nerve roots — unilateral or bilateral.

Common coding pitfalls

The recurring mistakes coders make with M42.9 and adjacent codes.

Source · Editorial brief grounded in CDC ICD-10-CM tabular guidance, AAOS coding references, and cited references ↓

Using M42.9 when the record documents a specific spinal region: site-specific M42.0x or M42.1x subcodes are available and required when laterality/region is known.
Conflating spinal osteochondrosis with intervertebral disc degeneration (M51.3x) or spondylosis (M47.xx) — these are distinct conditions with their own code families; verify the provider's intended diagnosis before coding.
Failing to query the provider when 'spinal osteochondrosis' appears without age context: juvenile vs. adult is a clinical distinction that changes the code entirely.
Applying M42.9 to adult patients when M42.1x (adult osteochondrosis of spine, site-specific) would be billable with minimal additional documentation.
Confusing Scheuermann disease documentation as degenerative spondylosis — Scheuermann maps to M42.0x (juvenile), not to M47 or M51 codes.

Clinical context

Source · Editorial summary grounded in 5 cited references ↓

M42.9 is the fallback code within the M42 category when documentation fails to establish whether the condition is juvenile (M42.0x) or adult (M42.1x) osteochondrosis, and no specific spinal region is identified. It sits under Deforming Dorsopathies (M40–M43) in Chapter 13. Because it lacks both age subtype and anatomic site, it represents the least-specific billable option in the category and should only be used when the record genuinely cannot support a more granular code.

Spinal osteochondrosis involves pathological changes at the vertebral epiphyses. In juveniles, Scheuermann disease is the classic presentation, typically affecting the thoracic or thoracolumbar region with wedging of vertebral bodies and resultant kyphosis. In adults, the diagnosis overlaps conceptually with degenerative disc disease and intervertebral disc degeneration, though those conditions have their own distinct ICD-10-CM codes. When a provider documents 'spinal osteochondrosis' without specifying age or level, M42.9 applies — but query the provider before defaulting here.

For MS-DRG grouping purposes, M42.9 maps to DRGs 553 (Bone Diseases and Arthropathies with MCC) and 554 (without MCC). The code has been stable in the ICD-10-CM system since FY2016 and carries no changes in FY2026 (effective Oct 1, 2025).

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 5 cited references ↓

01When is M42.9 appropriate instead of M42.0x or M42.1x?

Use M42.9 only when the clinical documentation does not specify the patient's age category (juvenile vs. adult) AND does not identify a spinal region. If either piece of information is present, a more specific code within M42.0 or M42.1 is required.

02Does M42.9 require a 7th-character extension?

No. M42.9 is a 4-character code and does not use 7th-character extensions. The M42 category uses 5-character subcodes to capture site specificity, not injury encounter extensions.

03How does M42.9 differ from M51.3 (other thoracic, thoracolumbar, and lumbosacral intervertebral disc degeneration)?

M42.9 targets pathology at the vertebral ossification centers (epiphyses), while M51.3x codes target degenerative disc disease of the disc itself. The clinical distinction matters: query the provider if documentation is ambiguous between the two conditions.

04What DRGs does M42.9 map to?

Under MS-DRG v42.0, M42.9 groups to DRG 553 (Bone Diseases and Arthropathies with MCC) and DRG 554 (without MCC), per icd10data.com.

05Is Scheuermann disease coded with M42.9?

No. Scheuermann disease is a juvenile osteochondrosis of the spine and should be coded to M42.0x with the appropriate site subcode (e.g., M42.04 for the thoracic region). M42.9 is not appropriate when the specific condition and region are documented.

06Can M42.9 be used as a primary diagnosis for orthopedic procedures?

It is billable as a primary diagnosis, but payers may question medical necessity for surgical procedures when the diagnosis code is this nonspecific. A site-specific M42.0x or M42.1x code — or a more precise alternative — will better support procedure authorization and audit defense.

07What is the ICD-9-CM equivalent of M42.9?

M42.9 crosswalks to ICD-9-CM 732.0 (Juvenile osteochondrosis of spine) and 732.8 (Other specified forms of osteochondropathy), depending on clinical context. Confirm the crosswalk against the specific payer's mapping table for legacy claim comparisons.

Sources & references

Editorial content was developed using the following public sources. Last verified May 8, 2026.

01CDC ICD-10-CM Tabular List 2026 (effective Oct 1, 2025)
02
icd10data.com
https://www.icd10data.com/ICD10CM/Codes/M00-M99/M40-M43/M42-/M42.9
03
aapc.com
https://www.aapc.com/codes/icd-10-codes/M42.9
04
aapc.com
https://www.aapc.com/codes/icd-10-codes/M42
05
icd10data.com
https://www.icd10data.com/ICD10CM/Codes/M00-M99/M40-M43/M42-/M42.09

Mira Scribe

Mira's AI scribe captures the patient's age, the spinal region described in the clinical note, and any imaging findings referencing vertebral endplate irregularity, Schmorl nodes, or epiphyseal changes — the exact elements needed to move from unspecified M42.9 to a site-specific M42.0x or M42.1x code. Without that capture, coders default to the least-specific option, risking downcoding, payer queries, and missed DRG optimization.

See how Mira captures M42.9 documentation