Though it is not specifically mentioned, “thoracolumbar” likely only includes T12-L1, and “lumbosacral” probably only refers to the L5-S1 interspace. There is a strange rule for cervical disc disorders indicating that you should code to the most superior level of the disorder.
It is already included in the code. Likewise, don’t code sciatica (M54.3-) if you code for lumbar disc with radiculopathy. It would be redundant. On a side note, lumbar radiculopathy (M54.16) might be used if pain is not yet known to be due a disc, but it radiates from the lumbar spine.