It was either left over from a very, very long time ago when deferrals were included in an overall contribution % limit, or somebody just checked the wrong box. You are probably beginning to see that, while you might assume that everything in this field is done carefully and by experts, that's not the case. Looooong story short on this, you are right and they are wrong. The hard part is getting a company like ADP to concede that because they consider themselves to be the final authority and most people cave in. Probably going through your wife's employer is the best thing, but they are likely to simply rely on ADP for the "final" answer, so spell it all out like you did here with the SPD text etc etc, and I don't think anyone would mind including their responses as backup. Good luck!