A fifth of the price, plus taxes and shipping, is due when you order the device and the rest of the cost is paid in 4 monthly installments. That's a little different from the installment plan Amazon tested in December; that older plan spread 4 payments out over several quarters, not months. And that older program was only good for the Kindle Fire HDX.
The basic Kindle can be had for 5 payments of $13.80 (plus tax and shipping), while the Kindle Fire HD costs $27.80 per payment. You can find more information, and apply for the plan, on Amazon.
Are sales of Amazon's hardware slowing down, do you think?
When I wrote about that plan in December I argued that it was not a sign that Amazon had excess stock; it only included a single model and was not open to everyone, so it was arguably an experiment. But now that all of Amazon's hardware is available for low monthly payments, you have to wonder whether they are getting worried about sales.