Rising rents and a lack of leasing opportunities are sweeping the country, forcing Americans to put more money toward their rent than a down payment for a future home.

Renters paid $478.5 billion in total this year, a 3.8% increase from 2015, according to real estate website Zillow. Combined with increasing home values, heavier lender expectations of credit scores and rising interest rates that will push up monthly mortgage repayments, the American dream of owning a home might seem somewhere off in the distance.

“Saving for a down payment is one of the big challenges for renters,” said Aaron Terrazas, a senior economist at Zillow. The ideal portion of income going toward rent is anywhere between 0% and 30%, he said, though that isn’t always feasible in certain cities. Anything more and the ability to save becomes less likely.

See:This is what $1,500 rent gets you in America’s biggest cities

First-time homebuyers are changing up the way they fund their first homes, Terrazas said. Traditionally, paying for a down payment simply involved saving, but these days shoppers are using multiple vehicles, including savings for the home as well as retirement assets, selling stock, and loans or gifts from family and friends. Some are even buying multi-unit homes and collecting rent to offset their mortgages. During the housing bubble years in 2004 and 2005, people were buying homes by taking loans out for the property itself as well as the down payment, which significantly increased the risk associated with the purchase and has largely disappeared, he said.

Not only are there not enough properties available for rent, but there aren’t enough homes on the market for sale either, said Greg McBride, chief financial analyst at personal finance website Bankrate.com. Those that want to purchase a home may be renting because they continue to be outbid on a home, likely due to stagnant incomes. With wages beginning to grow again, there may be relief in the squeezed housing inventory, especially for middle class-priced homes, he said. “Unfortunately, the spike in mortgage rates is likely to offset that even temporarily,” he added.

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But not everyone is hurting by the idea of renting for now, or ever. Renting makes sense for those looking for geographic flexibility, due to career or lifestyle choices. Millennials, who many have criticized for not buying homes at the same age or pace as their predecessors, might also be renting with a bunch of roommates or with their parents until they have enough saved for a home or paying their way through higher education to earn a salary that pushes them well past a typical starter home, McBride said. Of course it doesn’t help that many may be priced out at the moment, either: the housing market is worth $29.6 trillion, and buying a home has become more expensive, Zillow research found.

See: 5 tips for buying your first home