Tickseed - coreopsis - doesn't really need to be pruned. And pruning hard in autumn may compromise its ability to winter over well. You can just do a final deadhead later in the season but then it is suggested to just leave it be until spring clean-up time. Unless you find it reseeds heavily for you, then you might want to shear it back some in mid-late September to remove any vestige of flowers or seed heads. But I would avoid taking it back to the ground.

That's great to know, thanks very much.

We're in zone 5. I also deadhead every few days and at the end of the growing season have and do cut back Coreopsis cultivars to ground level. In the interests of garden hygiene my mixed-perennial-bed clean up is completed before the onset of winter.

This likely is a matter of growing location, style of perennial gardening and personal taste.

I usually cut back the thread leafed types in the fall.