Yes, the lumbar cushion and the head cushion are separate and are attached to the chair with elastic straps.

I was able to "test-sit" the HP Omen Citadel at a colleague's place and wasn't sure if I really needed the lumbar cushion. Then I waited a few weeks for the Citadel and when it arrived I immediately set it up in my home office with the cushion. I have to say that I wouldn't want to do without it! It can be adjusted in height (position) and supports the back perfectly. But it can also be removed, just like the neck pillow. One of the best purchases I have made for work in the last 10 years!