This summer I've been completing an internship and doing research under the supervision of a physician. A goal of mine is to ask him for a letter of recommendation for when I apply to medical school, which will likely be next summer (I'm a rising junior). My question is, should I ask him if he'd be willing to write my letter NOW, when the work I've done with him is still recent, or should I wait for when I actually need it? I don't know what the standard protocol here is, so any advice would be appreciated. My hesitation to ask now is because I'm not entirely sure how the AMCAS process works (please excuse my ignorance, that's why I've joined this forum) and I'm worried that all LOR have to be submitted from the author privately or through a secure link or something. If this is the case, I don't see how getting a letter now will do any good bc he will have to resubmit it later, granted I can still get in contact with him. One final question, although not completely related: I'm interested in becoming an MD but my PI is a DO. Does this matter at all as far as letters of rec go? Thanks for the help.