Asking for reversing my decision after declining a PhD offer I received a great PhD offer from University A (in the US) and after a very hard time making decision, I ended up not accepting it for family reasons and instead I accepted an offer from University B (not in the US) (because if I go to A, I most probably wouldn't be able to visit my family at all for 5 years, whereas I'll have the option to do that with my current choice, B). I explained this reason to the department chair after declining the offer and expressed my regrets for this issue stopping me from doing my PhD at A in a field I always dreamt about. 

Now, over a month after April 15, a few things has happened that I regret what I did, and I really want to change my decision and tolerate those years of distance from my family but go to A:


Perhaps most importantly, the 2-body problem: My partner just
got an amazing offer near A, and while she may also get an almost
equally-amazing offer from somewhere near B, the one near A would be still more tempting for her.
My realization evolved. A is a world top-10 in the field, but
that field is a field I have very little background in! I always
dreamt about working in that field, but never thought I could actually do
that and spent my entire academic life in a different field.
So, I think I was still confused about the opportunity I was given,
didn't quite appreciate it, and frankly, was very scared. This is
while B, a top-tier in the world in my undergrad field, is an
institution I always knew and it wasn't hard to fully appreciate the
offer from there. In the past month, my understanding about myself
and my situation has evolved, and I regret my decision.


My questions:


Would it be acceptable if I contact the department at A again and explain these two reasons and ask if they could still take me in?! It's been so long since 4/15, but I think there's a chance they didn't actually fill in all the available spots for the position as I declined on 4/15. Would I destroy my reputation among the academics at A if I do ask if I could reverse my decision now? I'm afraid I may sound immature and unable of making a decision (which is obviously not too wrong, I did have issues, and was indeed too slow in getting to know myself from the time I received the unexpected offer until 4/15).
If you think I can ask for reconsideration, who should I contact and is it better to emphasize on point 1 or 2?
I suggest you contact the department, minimizing overly personal details - but basically outlining that the life situation that caused you to decline their offer changed unexpectedly, and you would like to know if it would be possible to attend after all.

It is basically down to: 1) no, spot is no longer available or they can't extend/re-extend the offer, but you can probably reapply next year, no guarantees; 2) sure, that is possible, 3) it depends, they will ask additional questions or want to talk to you more before rendering a decision.

If you are professional in the communication then it will not cause everyone to look down on you, all reasonable people know life situations can change unexpectedly. It really isn't that big of a deal, they can either help or they can't/won't. 

As for who to contact, I would tend to suggest whoever contacted you with the offer and/or the person who you contacted to decline. As for what to emphasize, I'd just keep it simple and relate it most directly to why you declined in the first place, but try not to over-explain. Perhaps you just realized that there are ways to mitigate being away from family that you had not considered, or that you will have other family you can visit, or just that you'll end up having to be away from some parts of your family regardless so you'd rather persue something you are passionate about rather than stick with the familiar - etc. A sentence or two is probably all you need to include in the first contact - the situation has changed and you just want to see if attending would still be an option.

The only other thing you should be clear about is that you are in a position to accept such an offer from A - i.e., you have not already accepted a mutually-exclusive offer from another US graduate school, as that will tend to create additional bureaucratic resistance (such as needing a statement from the other school, etc.). 

It might be an option, or it just might not, but so long as you act reasonably (maybe have an especially rational friend read your email before you send it to make sure you keep it short and professional) there is no long time harm in asking. Life happens - good luck, regardless!