Although Cushing quickly visited the Seahawks and had a visit lined up with the Raiders that was canceled after Oakland signed Derrick Johnson, Cushing did not sign anywhere. The 2018 NFL season was the first one since the Texans selected him in the first round of the 2009 NFL Draft that Cushing was not on an NFL roster.
Cushing never announced his retirement from the NFL, mind you. But the fact that he wasn’t employed last year likely meant he was effectively retired, whether it was by his choice or that of the league.