A transistor device may be provided, including a substrate; a buffer layer arranged over the substrate; a source terminal, a drain terminal, and a gate terminal arranged over the buffer layer; a barrier layer arranged over the buffer layer; and a passivation layer arranged over the barrier layer. The gate terminal may be arranged laterally between the source terminal and the drain terminal, the barrier layer may include a recess laterally between the gate terminal and the drain terminal, a part of the gate terminal may be arranged over the passivation layer and the passivation layer may extend into the recess of the barrier layer.