When is the best time to reach out to potential advisers while applying to PhD programs? I am specifically applying to computer science PhD programs in the US.  I have read the other posts similar to this, but I have some specific questions.

1) When is the best time to email professors I would like to work with to maximize my chance of admission to programs for Fall 2020?  I've seen lots of disagreeing advice. One post said that it was best to reach out right after application deadlines so the professor will remember your email.  This is what I have been planning to follow.

2) If my contact with the professor goes well, is there a risk I could be "locked in" or risk damaging my relationship with them?  Say I reached out this week, if they  said I would be a good fit would I be expected to reply now?  Or could I wait until I hear from other schools in February/March?

3) How do I balance these concerns of maximizing my chance of admission and being "locked in"?

**I only plan to email professors that have specifically mentioned on there web page that they wish to be directly contacted by potential PhD students.  Any other advice is welcome.

Thanks.
1) In my experience, it’s never too early to reach out to someone you’d like to work with. I think it’s perfectly reasonable to send the professor an email indicating that you’re considering applying to their group and that you’d like to hear more about their research &amp; determine if you’d be a good fit. This saves you both time if you find out it isn’t a good fit.

2) I don’t think you need to worry about getting “locked in.” The professors will understand that you’re exploring your options, and you can emphasize as much in your conversation. You’re just exploring a potential collaboration - you’re not committed until you accept the admission offer.

3) A personal relationship with a potential advisor is, in my experience, a great asset during the admission process. Again, they will understand that you’re exploring multiple options. Just conduct yourself respectfully and professionally and there should be no hard feelings. (Thank them for their time, be up front about your goals and intentions, etc.) And besides, this won’t be time wasted: even if you end up choosing another University, there is always the possibility of collaborating with or being co-advised by the other professor.

**Of course, this advice is subject to any professor’s expressed preferences. If they say “let’s talk after admission decisions” - that’s fine! If they say on their website “feel free to contact me if interested in joining my group” - great! If they don’t respond to your initial email (perhaps +1 reminder email) - no worries!