The Boy Scout motto is "be prepared;" make it your mantra when planning a trip with your 2 year old in tow. First things first -- check your airline's website ahead of time for rules, regulations and possible schedule changes. Have your ID readily available for airport security personnel, and if your child needs identification, have it on hand as well.
The Transportation Safety Administration is required to screen everyone, regardless of age, but they do not need to see ID for every air traveler. Children under the age of 18 traveling with their parents are not required to provide identification when flying within the United States.
According to the U.S. Department of State, all minors, regardless of age and including newborns and infants, must have their own passport when traveling internationally by air. The process of getting a passport can take several weeks, so begin the process long before your travel dates.
Children will not be asked to separate from their parents. If your 2 year old can walk independently, he will be expected to walk through a metal detector on his own. If your 2 year old has a condition or disability making the security screening process difficult, inform the Transportation Security Officer so modifications can be made.
Pack travel-sized lotions and gels in a clear, plastic bag before heading for the airport. Tuck it into the outside pocket of your diaper bag or carry-on so it's easy to remove prior to the security check. Your child can leave his shoes on, but you'll have to remove yours. Wear slip-on shoes to expedite this process and minimize the number of times that you'll need to let go of your child's hand.