When do I rack?

My apple cider has been in the carboy for three weeks now and the specific gravity seems to be holding at 1.020 for the last two weeks. There is at least and inch and a half of sediment in the bottom of the carboy. I was wondering if I can rack my cider off into another carboy and then continue fermentation or do I have to wait until SG is 1.000 to rack it off the sediment? This is my first attempt at hard cider so I’m a little nervous.

You can rack or not. It probably doesn’t matter, if your gravity is already holding steady. If fermentation is still going on, it will slow down the fermentation even more. So if you want the cider to be finished as quickly as possible, do not rack it yet.

Ok so now a month after my last post my cider is still at a specific gravity of 1.020. Everything that I have read says cider should finish at or below 1.000. Should I add more yeast? Or a nutrient for my yeast? Or should I just accept that this is it for my cider?

I would just accept it. Light in alcohol perhaps but should be very tasty. If you want more alcohol you could add a little sugar and some fresh yeast. But I wouldn’t.