American Airlines  
Fare Domestic International
Description
 
A First Class First Class First Class, Oneworld Explorer, and from coach on 2-class flight using miles/VIPOW
 
B Yes Yes Full-fare 2nd tier; usu. 3-day adv. purchase, generally unrestricted, refundable
C NA Business Upgrade Full Fare Unrestricted Business Class. Upgradeable to F domestically.
D NA  Business Fare Discounted Business fare and Round the World Explorer
E  No  No 'Employee travelling on A12 (or A9 - family emergency)
F First Class/Award First Class/Award International or 2-class domestic. Also AAnytime award travel
G Government Government Government fares
H Yes*  No 3rd Tier, discounted economy Class with few restrictions.
I NA Business Fare Group Business Fare
J NA Business Fare Full fare Business Class. Also, AA Anytime Award.
K Yes No 4th tier economy; discount refundable changeable fare (e.g. K26d). Also, Air/sea fares (cruise+flight packages)
L Yes No  10th tier, discount economy promotional fares; seat sales; webspecials
M Yes No 5th tier economy. Also, RTW Explorer Coach Award
N Yes No  9th tier economy
O No   No  11th tier, discounted economy, consolidator fares
P First Class First Class Premium transcontinental Flagship service. Domestic first class on 3-class flights
Q Yes No 7th tier discounted economy. Consolidator fare for travel ex-Europe
R NA Business Upgrade Upgrade from coach using e-upgrades. Also, from full Y on int'l flights using TRANSUPG
S Yes* No  8th tier AA Vacations special discount fare
T Coach Award No  Plan AAhead (?) Award travel
U NA Business Award Plan AAhead Award travel
V Yes* No 6th tier, discounted coach
W Yes* No Air/sea fares (cruise+flight packages)
X FC Upgrade Business Upgrade First Class UPGRADE AWARD from paid Business* (Better known as 'NF'). Also, from full J on int'l flights using TRANSUPG
Y Yes Yes  1st Tier, Full Fare unrestricted economy class
Z FC Award NA Plan AAhead Award travel
 

Code Description
X Coach
X First / Business Elite
Yes Fare is Upgradeable
No Fare is NOT Upgradeable
NA Not Applicable
? Unknown

*AA Elite members can upgrade only. Please keep in mind that AAdvantage Executive Platinum members receive complimentary upgrades on any eligible purchased published fare. AAdvantage Platinum and AAdvantage Gold members receive complimentary upgrades when buying full-fare economy class tickets (booked in Y or B, excluding military/government fares).

AA fare codes for economy class in this order: Y, B, H, K, M, V, Q, S, N, L, O

Fare codes sorted by type:

Coach excursion fares are: B, H, K, M, V, N, L, Q
Employees: E
Government: Y/L
Youth/student international: H/K
Military: H/M Promotional (e.g. VUSA - Visit USA): L
NetsAAvers: L
Bereavement: M
Consolidator: K, W, V, L, O
Air/sea: W, K
RTW: M (coach), D (business), A (first)