| M540 | Panniculitis affecting regions of neck and back |
| M5400 | Panniculitis affecting regions of neck and back, site unspecified |
| M5401 | Panniculitis affecting regions of neck and back, occipito-atlanto-axial region |
| M5402 | Panniculitis affecting regions of neck and back, cervical region |
| M5403 | Panniculitis affecting regions of neck and back, cervicothoracic region |
| M5404 | Panniculitis affecting regions of neck and back, thoracic region |
| M5405 | Panniculitis affecting regions of neck/bk, thoracolum region Panniculitis affecting regions of neck and back, thoracolumbar region |
| M5406 | Panniculitis affecting regions of neck and back, lumbar region |
| M5407 | Panniculitis affecting regions of neck and back, lumbosacral region |
| M5408 | Panniculitis affecting regions of neck and back, sacral and sacrococcygeal region |
| M5409 | Panniculitis affecting regions, neck and back, multiple sites in spine |
| M541 | Radiculopathy |
| M5410 | Radiculopathy, site unspecified |
| M5411 | Radiculopathy, occipito-atlanto-axial region |
| M5412 | Radiculopathy, cervical region |
| M5413 | Radiculopathy, cervicothoracic region |
| M5414 | Radiculopathy, thoracic region |
| M5415 | Radiculopathy, thoracolumbar region |
| M5416 | Radiculopathy, lumbar region |
| M5417 | Radiculopathy, lumbosacral region |
| M5418 | Radiculopathy, sacral and sacrococcygeal region |
| M542 | Cervicalgia |
| M543 | Sciatica |
| M5430 | Sciatica, unspecified side |
| M5431 | Sciatica, right side |
| M5432 | Sciatica, left side |
| M544 | Lumbago with sciatica |
| M5440 | Lumbago with sciatica, unspecified side |
| M5441 | Lumbago with sciatica, right side |
| M5442 | Lumbago with sciatica, left side |
| M545 | Low back pain |
| M5450 | Low back pain, unspecified |
| M5451 | Vertebrogenic low back pain |
| M5459 | Other low back pain |
| M546 | Pain in thoracic spine |
| M548 | Other dorsalgia |
| M5481 | Occipital neuralgia |
| M5489 | Other dorsalgia |
| M549 | Dorsalgia, unspecified |
| M60 | Myositis |
| M600 | Infective myositis |
| M6000 | Infective myositis, unspecified site |
| M60000 | Infective myositis, unspecified right arm |
| M60001 | Infective myositis, unspecified left arm |
| M60002 | Infective myositis, unspecified arm |
| M60003 | Infective myositis, unspecified right leg |
| M60004 | Infective myositis, unspecified left leg |
| M60005 | Infective myositis, unspecified leg |
| M60009 | Infective myositis, unspecified site |
| M6001 | Infective myositis, shoulder |