When residents at Sun City Center, a sprawling retirement community in West Central Florida, struggle with their electronics, many of them now know who to call on: Maria Hodge, one of their newest residents, and also one of their youngest.

Since moving to this 55-plus community last year, Ms. Hodge, 59, has become a fixture among the nearly 11,500 residents, where the average age is 79. She cooks a weekly lunch for the volunteer EMT team. She serves as secretary of the synchronized swim team. She regularly dons a crisp laminated name badge and rides her golf cart over to the community information center to give tours to prospective new residents, gushing about its dance hall and fitness center, its art studios and woodcarving rooms, and its dozens of unique neighborhoods clustered around gardens and 90 small lakes.

But one of her favorite activities these days is tech support.

“We have people here who still have what we call the dino-phone,” she said. “They still have flip phones. And most of the women on my swim team are challenged when it comes to electronics.”

Ms. Hodge, a native of Cherry Hill, N.J., never imagined she’d settle in a retirement community well before her 60th birthday, but here she is a spring snowbird living in a community of people old enough to be her parents.

There are thousands of 55-plus communities scattered across the United States, with the majority clustered in Florida and the Southwest. Unlike assisted living and nursing homes, 55-plus communities offer older Americans an option to purchase traditional single-family homes but tap into a built-in network of friendship, extracurricular activities and an active, age-appropriate lifestyle that fits their needs as they enter retirement. In general, they require at least one member of a household to be 55 years old or older, and nearly all are governed by a homeowners’ association that collects dues to cover the costs of activities, community events and facilities.