National masters and above get a free diamond membership.
Free Membership for NM

CM and above with proof.
http://www.chess.com/members/titled_players.html
http://www.chess.com/forum/view/chess-players/nm-vs-cm

Holy cow!!! That's awesome. I just joined chess.com (as a diamond member, after a year of non-activity) and I am 3 USCF points away from earning my National Master title. So exciting! I'd be tickled pink to have a free diamond membership here.
One technical question; is it to those with the NM title that free diamond membership is given? Or must one also remain above 2200? (A USCF NM could be rated as low as 2000, or lower.)
Also, who should one contact if one is indeed an NM?
Thanks!!

Yes, I did make it! http://www.uschess.org/msa/XtblMain.php?201106187731-12630415
But I don't understand what you mean by yellow. Where do you see that?
in the forums your bar that has your name and everything is yellow. everyone elses is some sort of green or grey or something. of course, you also get the bold red NM next to your name.

Yep, titled players get that lightened background (actually, not for me because of my custom theme).

National masters and above get a free diamond membership.
Even CMs and FMs do - see http://www.chess.com/members/view/Kacparov and http://www.chess.com/members/view/FM_Eric_Schiller.

National masters and above get a free diamond membership.
Even CMs and FMs do - see http://www.chess.com/members/view/Kacparov and http://www.chess.com/members/view/FM_Eric_Schiller.
Both of those are higher than NM.

National masters and above get a free diamond membership.
Even CMs and FMs do - see http://www.chess.com/members/view/Kacparov and http://www.chess.com/members/view/FM_Eric_Schiller.
Both of those are higher than NM.
I wonder what's lower than NM (I'm inept at the rankings besides GM, IM, WGM, WIM)

FIDE CM is the same rating as USCF NM, but since FIDE ratings are a bit deflated, I consider it higher. There is a USCF CM title, but I don't think chess.com recognizes it.

I believe WFM and WCM, for 2100 and 2000 FIDE ratings respectively, are not recognised by chess.com.
You're right I forgot about the womens' titles.

National masters and above get a free diamond membership.
Even CMs and FMs do - see http://www.chess.com/members/view/Kacparov and http://www.chess.com/members/view/FM_Eric_Schiller.
Both of those are higher than NM.
I usually think of CM as a little harder to get than NM, but it really depends more on your history than anything. There are some players who have a FIDE rating history of 2200+ who can't seem to get their USCF ratings that high. It depends on your local talent pool.
Someone today floated a rumor about a free membership for National Masters, or maybe a free month of membership for someone who earns the title.
Is there any substance to this or any related variations on the idea?