https://www.gamespot.com/articles/amazon-prime-price-is-going-up-in-the-us/1100-6458556/

Amazon is raising the price of its annual Amazon Prime membership in the United States by a significant margin. The retail giant said today that the price will go up to $120 per year, up from $100. The price change goes into effect for new subscribers on May 11, while existing Prime subscribers will have to pay the 20 percent extra starting June 16 onwards.

An Amazon spokesperson confirmed to GameSpot sister site CNET that you cannot re-up at the lower rate if your renewal is comes up on or after June 16. This is just the second time Amazon has upped the Prime membership price; in 2014, it went from $80 to $100.