The Social Security Administration receives billions in free money each year from an unexpected source: undocumented immigrants. This group paid an estimated $25.7 billion in Social Security taxes in 2022, according to a recent analysis from the Institute on Taxation and Economic Policy, a left-leaning tax research group. Since unauthorized workers cannot collect retirement and other Social Security benefits without a change to their immigration status, the billions they pour into the program effectively act as a subsidy for American beneficiaries. President-elect Donald J. Trump has vowed to carry out the nation’s largest mass deportation program to date, and restrict legal pathways to immigration. It’s hard to predict whether the incoming administration will be able to follow through with its most aggressive promises, among them sending home the estimated 11 million undocumented immigrants currently in the United States, most of whom are of working age. But if the White House does follow through, economists project a broad drag on the economy — and it could cost Social Security roughly $20 billion in cash flow annually, according to actuaries at the Social Security Administration, which sends benefits to 68 million Americans each month, totaling $1.5 trillion last year. Social Security has faced a financing shortfall for years, partly because of demographic shifts. Falling birthrates mean fewer people are paying into the program, thousands of baby boomers are retiring daily, and retirees are collecting benefits for longer periods. “America’s demographic realities are increasingly challenging for financing programs like Social Security,” said Shai Akabas, executive director of the economic policy program at the Bipartisan Policy Center, a nonprofit. “Net immigration into the country is one factor that has positively pushed against that trend and helped fill the gap left by an aging work force.” The trust fund that pays Social Security’s retiree benefits is expected to run dry in 2033, when tax revenue will be enough to pay 79 percent of scheduled benefits. That means beneficiaries’ checks would be reduced by 21 percent if Congress did nothing. (Legislators are expected to do something, though there is a debate about the best approach to shore up the program.) Major shifts to immigration policy could have ripple effects on Social Security. The net immigration rate was projected to drive population growth — and account for all population increases beginning in 2040 because American fertility rates are so low, according to a 2024 report from the Congressional Budget Office. “If the immigrant work force declines, that will likely worsen Social Security’s financial picture in the near term and require more significant reforms elsewhere,” said Mr. Akabas of the Bipartisan Policy Center, which recently studied the issue. “That said, the broader questions of immigration policy and border security require careful thought that goes beyond their impact on the Social Security program.” To get a sense of how different levels of immigration — both lawful and otherwise — can alter the program’s finances over the long term, we can look at the Social Security Administration’s latest annual trustees report, which forecasts the financial health of the combined trust fund for retiree and disability benefits over a 75-year period starting in 2024. (Social Security’s shortfall is often measured as a percentage of the total payroll covered by the program, or all the wages subject to payroll taxes, the program’s dedicated funding source.)

Traveling off-season, booking early, playing with flexible dates and going somewhere off the beaten path are tried-and-true budget travel strategies. But each year brings traffic patterns and perennial sales that can cue savvy travelers on when to book and when to travel. Whatever the timing, it pays to shop for travel during low-demand spots on the calendar well in advance; that means usually booking domestic airfares 30 to 60 days out and international trips three to five months in advance. Reserve lodgings ahead, too, but make sure they are refundable so that if prices drop you can rebook at the lower rate. Caveats notwithstanding, the following are key times to put on your calendar for the best buys in travel. Advertisement SKIP ADVERTISEMENT January and February: ‘The best months’ The year kicks off with two of the cheapest months to travel — outside of ski destinations, anyhow. Most travelers have returned from holiday travel and kids are back in school, leaving those with flexible schedules a lot of leeway on where to go at low prices. “Prices are some of the lowest that you see throughout the year,” said Hayley Berg, the chief economist at the travel booking app Hopper, “and it’s a time of year where you can even book last-minute airfare, and still often get a deal.” For trips in January and February, fliers can expect to spend 15 percent less on flights and 45 percent less on hotel rooms compared with summer rates, according to the online travel agency Expedia. During those months, cities like Washington and Chicago lure visitors with dining and theater events in which meals and shows are discounted. New York now combines its dining, Broadway and hotel promotions in a single event, the NYC Winter Outing, Jan. 21 to Feb. 9. “My tip for finding the off-season in any destination is to Google a city and ‘restaurant week,’” said Samantha Brown, the host of the PBS travel show “Places to Love.” The period right after New Year’s isn’t just a good time to travel, but also to book trips further out. You may see tour sales — Exodus Adventure Travels has one through Jan. 20 — and Omio, the transportation booking app that covers trains, buses and ferries as well as flights, says January is the last chance to find low fares for European travel in May, June and July. ‘Wave season’ in cruising Sales in the cruise industry crest in the first quarter, January through March. This is wave season, when cruise lines issue some of their biggest booking incentives of the year. The offers aim to reach travelers as they are planning their summer vacations in a season when the promise of life at sea is more alluring than the views at home. Deals often take the form of inclusions or upgrades, but discounts can be found, too. Holland America Line released its wave season sale this year in December, offering departures from $129 per person per day in an upgraded cabin with a balcony. Princess has deals up to 40 percent off and $99 refundable deposits. The early bookings get ships off to a good start occupancy-wise and enable them to resist slashing future rates to fill cabins. Advertisement SKIP ADVERTISEMENT “Given the continued increase in travel overall and particularly in cruising, planning ahead can net a huge savings,” said Jenn Lee, the president of Vacation Planners, a travel agency network. ‘Dead weeks’ Busy spring breaks and busier summers seem to crowd out deals in prime months. But here and there, throughout the year, lie a few sweet spots that the travel industry calls dead weeks. “Dead weeks are defined by a total lull in travel when hotels and airfare are markedly lower,” Ms. Brown said. If you plan in advance, she added, airfares can be half off and hotels about a third off. Pockets of opportunity pepper the calendar. Expedia calls out the first week of March — roughly between Presidents’ Day and the onset of spring break — and the last week of April, for cheaper and less busy flights. The last two weeks of August can offer bargains, too, as long as you avoid Labor Day weekend. Late August fares average $140 less than peak summer fares, according to Expedia. Advertisement SKIP ADVERTISEMENT But the biggest dead period is right after Thanksgiving and before Christmas, a trough between peaks. There are exceptions — for example, European Christmas market destinations — but even among these, the first week of December can be a better time to visit before the holiday shopping throngs arrive. Consider a Caribbean vacation just before or just after Thanksgiving, advises Andrew Hedley, the director of business development at Tamarind Hills resort in Antigua. “The festive spirit begins to stir, but you’ll avoid the premium prices and packed resorts that come with the holidays,” Mr. Hedley said. The fall price slump Travel booking sites say airfares generally peak in June. But they usually come back down by September. Low fares tend to run through October. (Remember to book in advance to get the best deals). “The best time of the year, hands down, for domestic and most international trips is September and October when the prices typically drop about 30 percent of where they are in June,” said Ms. Berg, of Hopper. Advertisement SKIP ADVERTISEMENT According to the booking platform Vrbo, September is among the cheapest months to stay in a vacation rental. The reliability of fall as a better buy is being eroded in some destinations as travelers seek to escape the crowds and heat associated with summer travel. In a recent report, the high-end tour company Kensington said fall reservations in Europe rose nearly 5 percent over summer bookings. Beware of weather risks in tropical destinations in the fall, which coincides with the last few months of hurricane season. Year-end deals As a travel event, Black Friday has exploded in recent years as travel companies try to attract shoppers in the season of spending. Black Friday sales often start in early November and run through Cyber Week, or the week after Thanksgiving, which includes Travel Tuesday. Between Black Friday and Travel Tuesday, airfares run 25 to 30 percent below flights usually departing in January through May, according to Dollar Flight Club, a membership service that specializes in cheap airfares. Advertisement SKIP ADVERTISEMENT “The sweet spot for these deals is international flights, especially to Europe, Asia and the Caribbean, where airlines compete to attract early planners,” said Jesse Neugarten, the founder and chief executive of Dollar Flight Club. If Bermuda is on your list, check out the destination’s annual Pink Sale, which starts in late December and runs through January. Hotel offers tend to run 25 to 35 percent off for travel dates throughout the year. Travel agents call Christmas and New Year’s weeks “festive season,” when travel prices tend to spike with holiday traffic. But if you’re looking for a bargain city hotel, try the week leading up to Christmas. At HotelTonight, an app for last-minute hotel deals in 94 countries, rates on Christmas Eve go for about 37 percent less than they do on New Year’s Eve.