Is it possible to change your decision after April 15th?

[sumonewhoisntme]

I've seen posts regarding PhD decision-anxiety after the April 15th decision deadline, but most posts seem to have dealt with regret/anxieties over selecting one program over another after April 15th. I made the very difficult decision of turning down a fully funded offer but am now feeling some regret. I'm wondering if it's possible to change my mind now... (And, even if the department was able and willing to make it work, would this be too much of a faux pas?) The last thing I would want is to start off on bad terms with my department and advisors.

Has anyone else (either in this current cycle or past cycles) decided not to pursue any PhD offer and regretted their decision? Overall, how do you know if you made the "right" decision? How do you come to peace with your decision?

[PsyDuck90]

Honestly, chances are that your spot went to the next person on the waitlist after you declined the offer. You can reach out, but it is unlikely to come to anything. 

[lexileigh]

Last year I was accepted into a fully-funded program. I had heard not great things about the program, and it was in the middle of nowhere across the country. I spent a month trying to decide if I should just go because I got accepted somewhere, or if I should reject and try again the following year. I ended up rejecting the acceptance. Last year I wasn't sure I made the right decision, that thought creeping in my head often. What if I wasn't accepted this year? Ultimately, this ended up being one of the best decisions I could ever make. Regret is completely normal, but I ended up following my gut despite the many people who said I made the wrong decision. And now I was accepted at a much better fully-funded program in a city, as I always wanted!