M40.3Non-Billable (Header)Flatback syndromeChild CodesM40.30Flatback syndrome, site unspecifiedM40.35Flatback syndrome, thoracolumbar regionM40.36Flatback syndrome, lumbar regionM40.37Flatback syndrome, lumbosacral regionCode Hierarchy└M40Kyphosis and lordosis└M40.3Flatback syndrome└M40.3Flatback syndrome