How long do you bake a cod fish filet?

Bake a cod fish filet at 400°F (200°C) for about 12-15 minutes, depending on the thickness of the filet. The fish is done when it flakes easily with a fork and has an opaque appearance. Be careful not to overcook it, as cod can dry out quickly. Always check the internal temperature; it should reach 145°F (63°C).