The majority of millennials are showing little interest in carrying around a credit card.

In fact, a full 63 percent of those in this generation – people ages 18-29 – don’t even have one, according to a study by Bankrate.com, the online aggregator of lending rate information to consumers. 

That’s a significant departure from Gen Xers and baby boomers: only 35 percent of adults 30 and older don’t carry any credit cards in their wallets. 

About one-quarter of millennials (23 percent) carry one card, and 8 percent carry either two or three cards. 

Most Americans, of all ages, don’t bother to carry more than one card: only 21 percent of those 65 and older carry two cards, compared to18 percent of those aged 50-64, and 13 percent of those aged 30-49. 

A Gallup poll recently found that overall, Americans are tending to rely less on credit cards since the Great Recession, which partially explains younger Americans’ aversion to credit cards. 

There’s also the Credit Card Accountability, Responsibility and Disclosure Act of 2009, legislation borne of the financial crisis making it harder for anyone under 21 to get a credit card. 

Also, many millennials are carrying debt from historically high student loans, which may make them unqualified for a credit card. But the Bankrate study suggests that beyond that, millennials are simply uninterested in using credit cards. 

“Millennials grew up in a world where the economy was tanking,” explained David Pommerehn, senior counsel at the Consumer Bankers Association, who was quoted in Bankrate’s study. “There was great concern about jobs and debts and paying off bills.” 

Seeing their parents struggle through the financial crisis, and then coming into the working world with limited job prospects while carrying high student debt, has left many of these young Americans fearing the risk of paying with plastic. 

Of the few millennials that are choosing credit cards, only 40 percent are in the habit of paying off their balance every month. Most Americans over 30 (53 percent) pay off their monthly balance in its entirety. 

Without credit cards, it can be difficult to build a healthy credit rating. The Bankrate report details the conundrum of one Dallas-based millennial who struggled to get a $5,000 car loan from a bank, even though he had $30,000 in savings and was making $60,000 a year. 

The millennial had avoided credit cards in an effort to be frugal, and learned the hard way that going into debt proves you can pay it off, and that’s what lenders are looking for. 

According to Experian, a financial information services company that provides credit scores, the average credit score for millennials is 628, which is considered subprime by most lenders. 

Baby boomers have an average score of 700, and Gen Xers average 653. 

Millennials who try to save money by not carrying credit cards will see their credit rating drop because of it, and that will ultimately make the cost of getting a loan more if and when they do seek one out. 

“Millennials have to understand that it costs you money not to use credit just as it costs you money to use credit,” Mike Sullivan, director at Take Charge America, a nonprofit debt-counseling agency, said in the Bankrate study.