Kyphosis and lordosis (M40) ICD-10-CM
The M40 code range covers kyphosis and lordosis with 40 ICD-10-CM diagnosis codes. 31 of them are billable and valid for claim submission in fiscal year 2026, and the category headers group them but cannot themselves be billed.
Code First
Certain conditions have both an underlying etiology and multiple body system manifestations due to the underlying etiology. For such conditions, the ICD-10-CM has a coding convention that requires the underlying condition be sequenced first followed by the manifestation. Wherever such a combination exists, there is a "use additional code" note at the etiology code, and a "code first" note at the manifestation code. These instructional notes indicate the proper sequencing order of the codes, etiology followed by manifestation.
- underlying disease
Type 1 Excludes
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
Codes in the M40 Range 40 codes · 31 billable
- M40 Kyphosis and lordosisNon-billable
- M40.0 Postural kyphosisNon-billable
- M40.00 Postural kyphosis, site unspecified
- M40.03 Postural kyphosis, cervicothoracic region
- M40.04 Postural kyphosis, thoracic region
- M40.05 Postural kyphosis, thoracolumbar region
- M40.1 Other secondary kyphosisNon-billable
- M40.10 Other secondary kyphosis, site unspecified
- M40.12 Other secondary kyphosis, cervical region
- M40.13 Other secondary kyphosis, cervicothoracic region
- M40.14 Other secondary kyphosis, thoracic region
- M40.15 Other secondary kyphosis, thoracolumbar region
- M40.2 Other and unspecified kyphosisNon-billable
- M40.20 Unspecified kyphosisNon-billable
- M40.202 Unspecified kyphosis, cervical region
- M40.203 Unspecified kyphosis, cervicothoracic region
- M40.204 Unspecified kyphosis, thoracic region
- M40.205 Unspecified kyphosis, thoracolumbar region
- M40.209 Unspecified kyphosis, site unspecified
- M40.29 Other kyphosisNon-billable
- M40.292 Other kyphosis, cervical region
- M40.293 Other kyphosis, cervicothoracic region
- M40.294 Other kyphosis, thoracic region
- M40.295 Other kyphosis, thoracolumbar region
- M40.299 Other kyphosis, site unspecified
- M40.3 Flatback syndromeNon-billable
- M40.30 Flatback syndrome, site unspecified
- M40.35 Flatback syndrome, thoracolumbar region
- M40.36 Flatback syndrome, lumbar region
- M40.37 Flatback syndrome, lumbosacral region
- M40.4 Postural lordosisNon-billable
- M40.40 Postural lordosis, site unspecified
- M40.45 Postural lordosis, thoracolumbar region
- M40.46 Postural lordosis, lumbar region
- M40.47 Postural lordosis, lumbosacral region
- M40.5 Lordosis, unspecifiedNon-billable
- M40.50 Lordosis, unspecified, site unspecified
- M40.55 Lordosis, unspecified, thoracolumbar region
- M40.56 Lordosis, unspecified, lumbar region
- M40.57 Lordosis, unspecified, lumbosacral region
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the M40 range.
Kyphosis
Deformities of the SPINE characterized by an exaggerated convexity of the vertebral column. The forward bending of the thoracic region usually is more than 40 degrees. This deformity sometimes is called round back or hunchback.
Lordosis
The anterior concavity in the curvature of the lumbar and cervical spine as viewed from the side. The term usually refers to abnormally increased curvature (hollow back, saddle back, swayback). It does not include lordosis as normal mating posture in certain animals ( = POSTURE + SEX BEHAVIOR, ANIMAL).
Scheuermann Disease
A type of juvenile osteochondrosis affecting the fibrocartilaginous disc (INTERVERTEBRAL DISC) in the thoracic or thoracolumbar region of the SPINE. It is characterized by a forward concave SPINAL CURVATURE or KYPHOSIS.
Spine
The spinal or vertebral column.
About the M40 Code Range
ICD-10 code M40 covers diagnoses related to kyphosis and lordosis, two types of spinal curvature disorders. These codes are specifically used to identify variations and locations of abnormal spinal curvatures in patients, helping healthcare professionals accurately classify these conditions for diagnosis and treatment purposes.
The section includes postural kyphosis (codes like M40.00, M40.03, M40.04), which refers to abnormal outward curvature of the spine commonly known as “kyphosis deformity of spine” or “adolescent postural kyphosis.” Different codes distinguish affected spinal regions such as cervicothoracic or thoracic areas. Other secondary kyphosis (M40.10–M40.15) relates to kyphosis caused by underlying issues like injury or degenerative changes. The category of unspecified or other kyphosis (M40.20–M40.29) covers kyphosis types without clearly defined causes or locations and includes terms like “Dowager's hump” and “neuromuscular kyphosis.” For lordosis, codes beginning with M40.4 and M40.5 address conditions such as “postural lordosis” and unspecified lordosis deformities, sometimes called “hyperlordosis” or “loss of lumbar lordosis.” The ICD-10 code for lordosis helps document deformities related to excessive inward curvature of the lumbar spine. The flatback syndrome (M40.3) is also coded here, describing a loss or flattening of the normal lumbar curve. These distinctions allow medical coders to select the precise ICD-10 code for kyphosis or lordosis based on condition type and spinal region, enabling accurate clinical reporting and billing.
Questions About This Page
How many billable codes are in the M40 range?
Of the 40 codes in this range, 31 are billable and valid for claim submission from October 1, 2025 through September 30, 2026. Category header codes group them but cannot be reported on claims.
What does the M40 range classify?
The range classifies kyphosis and lordosis. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.
