American Express Membership Rewards - What happens to annual fee when canceling?

Just got hit with my $150 Gold card after 3 years of having the card. After getting chase sapphire and having a corporate plat card (and the benefits attached) I don't see much use for keeping Amex gold. I'm thinking about waiting until the next Delta transfer bonus and then dumping the card after transferring. Will I received a pro-rated refund of my annual fee?

In my experience yes, they have given me pro-rated refunds of cards canceled mid-term.