Getting an RFE deadline extension — my actual experience asking

Had a genuine, unexpected complication (a medical situation delaying a key reference letter) partway through my RFE response period and looked into whether an extension was possible. Sharing what I learned, since I hadn't seen this discussed much here. Extension requests aren't guaranteed and depend heavily on the specific circumstances and how the request is made — this isn't something to expect as routine, and I'd treat it as a genuine exception process for real, documented circumstances rather than a general timeline-management tool. My request was specific about the actual reason for the delay and included a realistic proposed timeline for completion, rather than a vague request for "more time." What I'd say to anyone considering this: it's worth knowing the option exists for genuine circumstances, but the much better strategy is building in enough buffer from the start that you don't need one. I didn't end up needing the extension in my case (the letter arrived just in time), but going through the process of researching it taught me it's a real but narrow option, not something to plan around having.