
Boynton Beach is a popular retirement destination in Palm Beach County, and there are a lot of 55+ communities there.
The only one I know of that is still currently building/selling new homes is Valencia Grand:

Valencia Del Mar elevates the renowned Valencia 55+ living experience in Boynton Beach, Florida. This luxurious new community offers innovative floorplans, cutting-edge features, and enhanced lifestyle options.
At its center is an 8-acre recreational site featuring a grand social hall, luxury restaurant with indoor and patio seating, stylish sports lounge, and world-class spa with steam rooms, saunas, and private treatment suites. Every aspect is designed for the discerning active adult.
Valencia Del Mar Information Form
Here's a look at what's currently on the market: