That’s low.

Indeed, the average credit score of a younger millennial (aged 22-28) is just 652 and of an older millennial (aged 29-35) just 665, according to data released Thursday by credit rating agency Experian.

That’s not great. Credit scores range from 300 – 850, with most scores falling somewhere in the 600-750 range. And while scores of roughly 800 and above are considered excellent, scores in the mid 600s — which is where millennials’ scores fall — are typically considered fair or merely good, which means they’ll likely have to pay more for everything from a mortgage to a credit card. (This guide will show you how scoring breaks down.)

Credit scores by age

Younger millennial (age 22-28) 652
Older millennial (age 29-35) 665
Gen X (age 36-50) 679
Boomer (age 51-71) 727

Why are millennials scores low? Rod Griffin, director of consumer education and awareness at Experian, says part of it may be that “because they are young and haven’t yet established a robust credit history.” Indeed, a young millennial might be barely out of college, and “at 22, most people have very little credit history and so would likely have lower credit scores,” he explains.

Low scores matter because they can end up costing you tens of thousands of dollars. The reason: People with lower scores are less likely, on average, to repay their debts, so the companies lending them money — like a credit card company or a mortgage company — will charge them higher interest rates to offset the risk they’re taking.

Here’s an example: Let’s say you’re borrowing $250,000 to buy a home and get a 30-year-loan, which is standard. If you had a score of 760 or higher, your mortgage rate might be something like 4.161%, according to FICO, a credit scoring company; that would mean the total interest you’d pay to the lender over the life of the 30-year loan would be $188,069. Now let’s say you have a score of 652 (the average for a younger millennial). In that case, your rate would be 5.204% — and you’d wind up paying $244,422 in interest, which is roughly $56,000 more than the person with the better score.

How much people with different credit scores pay on a $250,000 mortgage

 Source: FICO

And it’s not just mortgages that low scores impact. “A credit score can play a part in getting that new cell phone you want, in qualifying for an apartment lease, for setting up utility service with lower security deposits, and when applying for car or home insurance,” explains Griffin. “Having good credit scores can save you money by having to pay lower interest rates, reduced activation fees, lower security deposits, and reduced insurance rates.”

It could even impact the job you get. “A limited version of your credit report may be reviewed when you apply for a job or promotion, particularly for jobs that involve handling a company’s money or to verify our identity,” he adds. (Note that credit scores are not used for employment purposes, but credit reports may sometimes be.)

Here are five things you can do to raise your credit score.

  1. Establish a credit history, says Griffin. To do that, make sure you have bills like a credit card in your name, and that you pay them off in full and on time each month.
  2. Use automatic reminders so you always pay your bills on time. Payment history is the largest component of your FICO score, which is the credit score many lenders use to evaluate a borrower, making up 35% of your score. That means that you must pay your bills on time to raise your credit score. The easiest way to avoid forgetting to pay a bill: Set up automatic reminders on something like a Google calendar for all of your bills.
  3. Pay down your debts. Keep balances low on your credit cards and other lines of credit. One simple strategy for paying down multiple credit cards: Pay as much as you can on the highest interest card, the minimums on all others, and keep doing this until your debts are paid off.
  4. Keep unused credit card accounts open. Having available credit that isn’t all maxed out improves your score, which is why you should keep credit cards, even those you never use, open.
  5. Don’t apply for a bunch of credit cards or loans at one time. Instead, space out card and loan applications.