Dry Ice is allowed in both carry-on and checked bags, but conditions apply to both. Dry Ice is allowed with conditions in carry-on bags — Up to 5.5 lbs with airline approval; must be vented. Dry ice up to 5.5 pounds is allowed for perishable items. Package must allow CO2 gas to release. TSA officers have the final say on what is allowed through the checkpoint. If you are unsure, check the TSA website or ask an officer at the airport.
TSA generally allows solid food items in both carry-on and checked bags. However, foods with a spreadable, pourable, or gel-like consistency are classified as liquids and must follow the 3-1-1 rule. Frozen foods are allowed but may be subject to additional screening.
Dry Ice is allowed in carry-on bags with conditions. Up to 5.5 lbs with airline approval; must be vented. Make sure to comply with all requirements before arriving at the checkpoint.
Dry Ice is allowed in checked baggage with conditions.
Dry Ice is generally permitted, but a TSA officer may inspect it further. You might be asked to remove it from your bag for separate screening.
TSA rules apply at U.S. airports regardless of destination. However, your arrival country may have different import regulations for Dry Ice. Check the customs rules of your destination before packing.