Unmarried Cohabitation: Why More Americans Are Living Together Without Marriage

Twenty years ago, if you saw a couple living together without being married, you might’ve raised an eyebrow. Today, it’s normal. In fact, it’s becoming the default path for many young adults in the U.S. The idea that marriage is the only legitimate way to build a life with someone is fading fast. Unmarried cohabitation isn’t just a trend-it’s a structural shift in how Americans form relationships.

From Rare to Routine

In 1968, less than 1 in 1,000 people under 25 lived with a romantic partner outside of marriage. By 2018, that number jumped to nearly 1 in 10. For people between 25 and 34, the rise was even steeper-from 0.2% to 15%. That’s not a slow creep. That’s a full-on reversal of social norms. Today, more 18- to 24-year-olds live with an unmarried partner than with a spouse. That’s something we never saw before.

This isn’t just happening with young people. Cohabitation is growing fastest among those 65 and older. More seniors are choosing to live with partners after divorce or the death of a spouse, skipping remarriage entirely. It’s not about rebellion anymore. It’s about practicality, comfort, and changing expectations.

Why Now? The Real Reasons Behind the Shift

There’s no single cause. It’s a mix of money, culture, and timing.

The Great Recession changed everything. After 2008, young adults faced stagnant wages, student debt, and unaffordable housing. Marriage, with its legal and financial expectations, became a luxury many couldn’t afford. Living together was a way to split rent, share groceries, and survive without the pressure of a wedding.

At the same time, social stigma faded. Religious influence declined. Divorce rates, once feared, became normalized. People stopped seeing marriage as a requirement for legitimacy. Instead, they started seeing it as one option among many.

And then there’s the generational shift. Millennials and Gen Z grew up watching their parents divorce. They saw how messy marriage could be. So they’re taking their time. They want to test compatibility before making a lifelong commitment. For many, cohabitation isn’t a rejection of marriage-it’s a filter.

Marriage Isn’t Dead. It’s Just Different.

Here’s the twist: most people who live together now still plan to marry. About 75% of marriages today are preceded by cohabitation. That means living together isn’t replacing marriage-it’s becoming the first step.

But the nature of that step has changed. In the past, couples moved in together as a prelude to a wedding. Today, many stay cohabiting for years without ever tying the knot. The Institute for Family Studies found that among people born in the 1950s, 23% of cohabiting relationships turned into marriage within a year. For younger generations? Only 12%.

And it’s not just about timing. Marriage is losing its economic advantage. Back in the 1970s, married couples earned more, saved more, and built wealth faster. Today, that gap is narrowing. Cohabiting couples are catching up. They’re working, buying homes, and raising kids-just without the legal paperwork.

Who’s Doing It? The Demographics Behind the Numbers

Cohabitation isn’t evenly spread. It’s heavily tied to education and income.

People with college degrees are more likely to marry than those without. But even among the less educated, cohabitation is rising faster than marriage. Why? Because marriage requires more financial stability. Without it, people delay or skip it entirely.

According to the U.S. Census Bureau, nearly 13% of people living with a partner today are unmarried. That’s up from less than 1% in 1967. And it’s not just young adults. One in five adults aged 25-34 now lives with an unmarried partner. For those 65+, the growth is the fastest of any age group.

There’s also a gender gap. Women who cohabit before marriage tend to marry later than those who don’t. The National Center for Family & Marriage Research found that cohabitation delays marriage-not because women don’t want it, but because they’re waiting for the right person, the right job, the right moment.

What About Kids? The New Family Structure

More than 40% of births in the U.S. now happen to unmarried mothers. That’s up from just 5% in 1960. Many of these mothers are in long-term relationships, not single parenting by choice. They’re raising children with partners they live with-but haven’t married.

This is reshaping what a family looks like. The old model-husband, wife, kids-no longer fits most households. Today, you’re just as likely to find a two-parent home with unmarried partners as you are with married ones. And the kids? They don’t care. They just want stability, love, and food on the table.

But there’s a catch. Research shows children raised in cohabiting households are more likely to experience instability. Relationships tend to end more often than marriages. That’s not because cohabiting couples love their kids less. It’s because these relationships lack the legal and social scaffolding that marriage provides.

Stability, Money, and the Hidden Costs

Let’s be honest: cohabitation has trade-offs.

Studies from the Wharton Budget Model show cohabiting adults tend to earn less, work fewer hours, and have lower productivity than married peers. Why? Marriage creates incentives-financial, emotional, and social-to stay committed and build a future. Cohabitation doesn’t always do that.

Also, cohabiting couples report lower relationship quality than married ones. The Institute for Family Studies found that couples who live together before marriage are more likely to report dissatisfaction later. It’s not that cohabitation causes problems. It’s that it often attracts people who are uncertain about commitment.

And yet, most Americans support equal rights for cohabiting couples. A majority believe unmarried partners should have the same legal protections as married ones-healthcare access, inheritance rights, parental custody. Society may not see cohabitation as marriage, but it’s starting to treat it like one.

What’s Next? The Future of Relationships

By 2040, experts predict over 16% of U.S. adults will be cohabiting-up from just under 10% today. Meanwhile, the share of married adults could drop below 40%. That’s a historic low.

Gen Z is the most likely to never marry. Researchers estimate one in three will reach age 45 without ever tying the knot. That doesn’t mean they’re lonely. Many are in long-term relationships. They just don’t need the word “married” to feel secure.

But here’s the quiet irony: while cohabitation is rising, the number of unpartnered adults is shrinking. In 2019, 44% of U.S. adults were unpartnered. By 2023, that dropped to 42%. People aren’t becoming loners-they’re pairing up, just differently.

Marriage isn’t disappearing. It’s being redefined. The question isn’t whether people will live together. It’s whether society will catch up with the legal and emotional realities of these relationships.

It’s Not About Rejection. It’s About Reinvention.

Unmarried cohabitation isn’t a rebellion against marriage. It’s a response to a world that’s changed too fast for old rules to fit.

People aren’t avoiding commitment. They’re avoiding bad ones. They’re waiting for financial security, emotional readiness, and real compatibility-not just tradition.

And maybe that’s the point. We’re not losing marriage. We’re learning how to build better relationships-on our own terms.