(CNN) -- Are those airline baggage and cancellation fees taking a bite out of your wallet?
They're certainly making money for U.S. airlines, which collected $6.16 billion last year: $3.35 billion in baggage fees and $2.81 billion in reservation change fees, according to U.S. Department of Transportation data released Monday. That's a slight increase from $6.04 billion collected in 2012.
Those ancillary fees helped the 26 passenger U.S. airlines make a net profit of $12.7 billion in 2013, up from a profit of $98 million in 2012.
Delta Air Lines topped the list, collecting $1.67 billion last year: $840 million in reservation change/cancellation fees and $833 million in baggage fees. United Airlines came in second place, with $1.38 billion in fees: $756 million in reservation cancellation/change fees and nearly $625 million in baggage fees.
The new airline created by the merger of American Airlines and U.S. Airways, which are still reporting their data separately, would have topped the list if their fees were added together. The combined airline collected more than $1 billion in baggage fees and $848 million in reservation cancellation and change fees.
Reporting as two airlines, American ranked third in the reservation cancellation and change fee category, collecting $521 million in fees, while US Airways came in fourth place with $327 million. U.S. Airways was third for baggage fees with $528 million, while American collected $506 million to come in fourth.
American was the first U.S. airline to charge customers to check bags in June 2008, for a fee of $15. That year, American collected $277,991 in baggage fees, according to Department of Transportation data. Other U.S. airlines quickly followed suit, and as a group they collected $1.1 million that year.
Fees have since crept up; American now charges $25 for the first checked bag, with some exceptions.
Which extra fees do you pay for when you fly and which fees will you not pay? Please share in the comments section below.