Schedule A is also known by tax preparers and the IRS as Schedule A, Itemized Deductions. The Schedule A Form is the tax form that transfers all of a flight crewmember's individual itemized deductions directly to the flight crewmember's IRS Form 1040. Items such as medical and dental expenses, taxes paid, interest paid, gifts to charities, casualty and theft loss, etc., are all captured on Schedule A. Schedule A also receives the aviation-related travel expenses and employee business expenses from IRS Form 2106.

Think of Schedule A as a middle-man for itemized deductions.  Using an airline pilot's employee business expenses as an example, the pilot would enter all of those airline job expenses on IRS Form 2106 (EZPERDIEM.COM provides a simple online method to help pilots and flight attendants write off aviation-related employee business expenses, including the per diem deduction).  IRS Form 2106 has instructions on it to guide the taxpayer through what to do with each expense (example: M&IE, travel expenses).  Once complete, IRS Form 2106 has the airline pilot transfer the number generated on it over to Schedule A.  Schedule A makes adjustments (example: the 2% limit) to that value, and the number from Schedule A is then transferred to the airline pilot's IRS Form 1040.

If the airline pilot uses tax software packages such as TurboTax or TaxCut, then all of this transferring happens automatically, and all of the appropriate forms are generated based on the answers to the airline pilot's tax questions asked from the software package.