As Maria correctly stated, their are various rules in the many communities and you might be able to buy one and move in when you are 55. In addition, there are also a couple of newer communities that have very limited exemptions that can sell to 48-54 year olds. They are gobbled up very quickly but I can make a few phone calls for you to see if they have any openings.
The more than 90 55+ connunities in Ocean County have varied rules and regs. You can buy in many of them, but can't move in until you are 55.
Many potential buyers start their search early as to get a feel for the area. I can help you in your search if you like.