NMOS/PMOS Saturation
For NMOS, the conditions \$V_{GS}&gt;V_{TH}\$ and \$V_{DS}&gt;V_{GS}-V_{TH}\$ ensure saturation. 

So an NMOS in saturation can come out of saturation if the applied \$V_{GS}\$ is increased beyond \$V_{GS}=V_{DS}+V_{TH}\$.