The Panasonic PT-AR100U, comes standard with a one year warranty on parts and labor. They do not offer any form of loaner or replacement program.
In addition, over the past few years, Panasonic has, more often than not, offered a 2nd year warranty, upon registration, to encourage you to register. It seems that once again, Panasonic is offering all who will register in the US, that second year, at no charge.
Panasonic does limit the warranty to 2000 hours maximum on the projector.
That's just fine for occasional viewers (that's about 40 hours a week), but at least some folks who, like me, use their projectors typically as a primary television, that warranty isn't going to make it to the end of the year.
Bottom line, One year's what most of the competition have, but there are exceptions, including a couple of projectors with 3 year warranties, such as the Viewsonic Pro8200, which is even less expensive. The Epson 8350 costs more, but comes with 2 years and a replacement program, and so it goes.
As I always do, I warn of short (1 year warranties). Should your projector have an issue, shortly after a 1 year warranty ends, you've got a real problem, since most projector repairs are not inexpensive. For this reason I recommend a low cost 3rd party extended warranty when a longer warranty, or a factory warranty extension is not available. Generally, they can be more hassle, but, the low cost makes them a decent gamble. Consider, if that same projector makes it to shortly past 2 years before failing, then at least, two years later, a replacement probably will perform better, and cost less. In addition, your lamp will probably have a fair amount of hours on it and be about ready for replacement, so the real "costs" then, are much less.
Here's how it might look, with a 2 year - and failure after the two year warranty runs out: $999 projector fails, comparable replacement 2 years later, $799, better performance. Cost of repair $450, Cost of new lamp (assuming you've used about 80%) $349, but you only used $280 so far. So, basically, between the repair, and an imminent lamp replacement you are looking at over $700, and you end up with a repaired projector with no warranty but on the repair itself, vs. spending about an extra $100 for a new, improved projector, with a new warranty.