Pour broth into an Instant Pot®, then add macaroni, salt, pepper, and butter. Use a wooden spoon to stir. Place the lid on the Instant Pot® and click into place to close.
Press the Pressure Cook button and adjust the timer to 5 Minutes. When the timer beeps, quick-release the pressure until the float valve drops. Unlock lid.
Add in remaining ingredients, stirring until cheese is melted and fully incorporated. Serve warm