Most schools, you won't see any waitlist movement until May. The greatest movement tends to happen in the second part of May and early to mid June; after that, it continues but slows down. Occasionally you might see a few acceptances from waitlists in March or April but that occurs at schools that give out very few acceptances to begin with (only enough to equal spots in the class) so whenever they receive notice that someone is declining an acceptance they can pull someone new in to fill their spot. Some schools operate that way...but most schools give out an overabundance of acceptances compared to the number of spots they have, because they know that only a certain proportion of those accepted will attend. Basically, don't expect much waitlist movement till late May.