SOUTHBURY, Conn. — Judy Plouffe and her mom are big on mother/daughter outings in this picturesque suburb off Interstate 84.

There are Friday pizza nights with their neighbors in Heritage Village, van trips to the Danbury Fair Mall, and a full schedule of events at what used to be the town library. Ms. Plouffe is partial to the aerobics, pinochle and square dancing there. Her mother, Frances Lefevre, preferred the weightlifting, tai chi and Wii until health problems slowed her down, but she figures she is about ready to get back to some of her favored activities at the old library, and what is now the Southbury Senior Center.

“She does well,” said Ms. Plouffe, 64, a retired home health aide who, like her mother, is widowed. “She has problems, but any 92-year-old would. Me, I’m one of the kids around here.”

Elderly people are now a greater portion of the population than at any time since the government began keeping track, and the Northeast, not warm weather retirement Meccas like the South and Southwest, has the largest percentage of people 65 and older, according to the Census Bureau.

So Ms. Plouffe and her mother have made Southbury an intriguing snapshot of the graying of America. Once dairy farming country, it is now a place where the elderly are not just the dominant demographic but increasingly, the engine of the economy and the focus of town life. For now, it works. Long term, it may get more complicated.

“When Heritage Village first came in, it was us versus them,” said First Selectman Bill Davis, speaking about the sprawling 55-and-over complex with 1,000 acres and about 4,000 residents, which opened in 1967. “But now, almost anything we do we take them into account. That’s who we are. We’re an elderly-based community.”

More than 30 percent of Southbury’s population is over 60, a figure expected to be about 40 percent by 2020. Nationally, according to the 2010 census, the population over age 62 grew by 21 percent in a decade, compared with just 2.6 percent for those under 18. Maine had the highest median age, 42.7, followed by Vermont, West Virginia, New Hampshire, Florida, Pennsylvania and Connecticut, whose median age was 40.0. In 2000, no state had a median age above 40.

So in addition to Heritage Village, where the median age is 77, Southbury has a Grace Meadows public housing complex for the elderly, three assisted living centers, and two nursing homes — all in a town with less than 20,000 people — which provide an interdependent network of services. A resident of Heritage Village might spend time rehabbing at the River Glen Health Care Center after hip replacement or heart surgery, move back to Heritage Village or to an assisted living center like the Hearth at Southbury, Pomperaug Woods or the Watermark at East Hill or eventually relocate to the Lutheran Home, which specializes in dementia care.

It’s not quite a Yankee Shangri La, but to some residents it seems that way. Ronald Cooper, 70, a Southbury native, grew up on a local dairy farm without running water, electricity or heat other than the fireplace. He helped build Heritage Village, did various other jobs, then came back to work there as a maintenance foreman. On Thursdays he is one of 50 or so people — perhaps half a dozen of them male — who show up at the senior center for the weekly bingo game called by the 86-year-old Vincent Ditaranto.

“I see very little we could improve on,” Mr. Cooper said. “People complain about money and tax issues, and if you don’t have enough for proper health care, eyeglasses, medicine and all that, it’s a problem. Fortunately, I have four pensions. I’m not saying we’re rich, but we live comfortably.”

Of course, for many these days even comfort can seem elusive. Longtime residents cite a shortage of affordable housing for the elderly. The 88 units of public housing have a three-to-four-year waiting list with over 150 names.

Ms. Plouffe and her mother, a retired secretary, struggle to pay the ever rising maintenance fees, now almost $500 month, at Heritage Village. Scratch most people and you hear financial concerns.

“Almost everyone has lost a good part of their portfolio, their savings,” said Grethe Arthur, who at 79 ice skates and takes part in the exercise and photography classes at Heritage Village and the senior center. “Everyone’s feeling it, but they don’t want to talk about it.”

And Southbury and Connecticut, like much of the nation, face the titanic challenge of supporting its aging population. The solvency of Social Security and the rising costs of Medicare are two issues yet to be tackled, since the Congressional deficit reduction committee failed last month to reach any deal.

Benjamin Barnes, the state’s budget director, said Medicaid costs, which are shared with the federal government, are a pressing issue, already consuming $5 billion, a quarter of the state budget. One of the fastest-growing segments of Medicaid is nursing care, which the state has tried to address by encouraging home care as an alternative to more costly institutionalized care. “Health care cost containment is a big challenge for us in the long term, and obviously an aging population is one of the demographic trends working against us,” he said.

Beyond that, he said, local and state tax revenues face growing pressure as people live on pensions instead of salaries and health care costs leave less discretionary income. “If someone goes on a pension and their income is cut in half, thinking as the tax man, I just lost half their taxes,” he said.

But there are economic upsides, too, in having so many retirees around. Southbury is sending fewer students to school but still providing tax revenue to the school district. They volunteer in great numbers at local agencies and churches. In Connecticut Magazine’s statistical rating of the best towns in its size, Southbury ranked eighth, between the tony towns of Madison and Stonington.

And if the future is uncertain, Southbury, with its ample open space and tidy, upscale strip centers, does not show it. The town’s Senior Resource Guide shows why, with its ads for elder-care lawyers, cardiac and joint replacement medical care, home health care, upscale residences and hearing aid companies.

At the senior center, which opened four years ago, the struggle is often figuring out which activities to do — Pilates or Fit and Flex? Line dancing or tap dancing? Photos for Fun or table tennis? Five drivers deliver the elderly there or to other places in town in four vehicles, including a 14-passenger van.

With two replacement knees, Evelyn Bowen, the 77-year-old widow of a Brooklyn chiropractor, does aerobics, armchair yoga, tap and Spanish castanet dancing, plays bingo Thursday at the senior center and calls bingo Friday at the Village. She’s in the Celtic Club, the Italian Renaissance Club and the Hadassah Women’s Club when she’s not spending the winter in Florida.

“I’m still partial to New York, but this is a much calmer place to live,” she said. “No one’s rushing here, there and everywhere.”

Everett Park Hopkins, 88, who heads the senior center photography club, said that politics are relatively simple here: most people just want to make sure their benefits are protected and their taxes kept down. “That’s very nice if you can do it,” he said.

Solving the big problems may be the task for another generation. At the senior center, they are handling smaller, more immediate challenges.

Mr. Hopkins was driving Ms. Arthur home to Heritage Village after their photography class the other day. But first, he had to get up from his chair. He scrunched forward, leaned hard on the armrests and with her help made it up.

“On top of everything else, she’s strong,” he said as the two walked slowly toward the exit.