Hello, 

The difference between box 14 of T4 and box A of RL1 can be related to box J. Box J is the amount paid by the employer to a private plan and is a taxable benefit in Quebec.  If you have an amount in Box J of the RL-1, ignore this amount as it is a taxable benefit that can be claimed as a medical expense in Quebec only, while for residents of other provinces/territories this amount cannot be claimed as a medical expense nor it's a taxable benefit and not included in box 14.