How Do I Stop a Pokemon From Leveling Up?

Since the release of the first "Pokemon" game for the original Game Boy handheld, the method of raising your Pokemon has been the same: use your Pokemon in battle so that they may gain experience and level up. So long as a Pokemon makes an appearance in a battle, that Pokemon will gain experience and level up over time. If, for any reason, however, you want to prevent your Pokemon from leveling up, you must prevent that Pokemon from entering a battle at all costs.

Preventing Your Pokemon From Entering a Battle

Press the "Start" button to open up the game's menu.

Scroll down to the "Pokemon" option and press the "A" button.

Scroll down to the Pokemon that you do not want to level up and press the "A" button. Scroll down to the "Switch" option and press the "A" button.

Scroll down to the sixth Pokemon slot and press the "A" button to place the Pokemon in the last Pokemon slot. Now, when you enter a battle, the Pokemon will not immediately enter the battle, meaning it will not gain any experience. If the Pokemon does enter the battle for any reason, however, it will gain experience and potentially level up.

Placing the Pokemon in Storage

Enter the Pokemon Center in the town you find yourself it. Every town has a Pokemon center, designated by the word "Poke" written on the door or a red roof.

Approach the PC in the Pokemon Center and press the "A" button.

Scroll down to the "Pokemon Storage System" option and press the "A" button.

Scroll down to the "Deposit" option and press the "A" button.

Highlight the Pokemon that you want to deposit and press the "A" button. Scroll down to the "Deposit" option and press the "A" button to remove the Pokemon from your party. So long as the Pokemon is not in your party, it will not gain experience and will not level up.