If you’re carrying a balance on a high-interest credit card or you need to make a purchase that you can’t pay off for a while, you could be throwing money away. Right now there are credit cards available that feature absolutely zero interest payments for substantial lengths of time, allowing you to save money on interest fees. In fact, Citi (a NextAdvisor advertiser) just lengthened the 0% introductory APR period on its top two 0% APR cards to 21 months, the longest 0% intro APR period we’ve found and the longest we’ve seen from a major issuer since we’ve been reviewing credit cards. You can take advantage of these cards to pay down your balance interest-free, almost like a free loan.  The 21-month 0% intro APR period will take you straight into 2017 without paying a dime in interest. If you are paying credit card interest now or will be in the near future, you should take a close look at these cards:

Citi Simplicity
With a staggering 21-month 0% intro APR on both balance transfers and purchases, Citi Simplicity is interest-free until 2017. In addition, there are no late fees and no penalty rates, benefits few other cards offer. Plus, there is no annual fee so you don’t have to worry about a yearly charge. With the lengthy 21-month 0% APR you can make new purchases or transfer your existing balances from high-interest cards over to this one and sail interest-free into 2017. There is a 3% balance transfer fee, but depending upon the amount you transfer and what you’re currently paying in interest fees it could definitely be worth it. If you’re not sure, use our free Balance Transfer Calculator to see if this is the right card for you.

Citi Diamond Preferred
Citi Diamond Preferred also starts off with a 0% APR for 21 months on balance transfers and purchases, but adds some extra perks. You’ll also get Concierge Service and access to presale tickets via Citi Private Pass. Plus you’ll earn Citi Easy Deal points with each card purchase (a $10 purchase = 1 point) that you can redeem for discounts on online merchandise, gift cards, travel and entertainment. With the 21-month 0% APR you can easily transfer any outstanding balances you have onto this card and pay them off interest-free over the course of the next 21 months. You can also make any large (or small) purchases you’ve had your eye on and pay no interest until 2017. The card does have a 3% balance transfer fee, which could be totally worth it depending upon how much you’re transferring. You can check out our Balance Transfer Calculator to see if this card is the right choice for your situation.

These cards may not have the incredibly long 21-month 0% APR the other cards do, but they’re still worth a good look:

Chase Slate
If you’re concerned about paying a balance transfer fee, consider Chase Slate. With absolutely no balance transfers fee, no penalty rate and no annual fee and a 15-month 0% intro APR on balance transfers and purchases, this card can save you some serious money. You won’t pay a dime to move your outstanding balances onto Chase Slate and you won’t pay any interest until well into 2016. Plus if you happen to be late on your monthly payment Chase won’t raise your interest rate. As an added perk you’ll get your Experian FICO score every month for free, which will help you keep close tabs on your Experian credit history.

Blue Cash Preferred from American Express
In the market for a card that combines great cash back rewards with a lengthy 0% APR period? Blue Cash Preferred from American Express (a NextAdvisor advertiser) features a 0% intro APR for 15-months on purchases and balance transfers as well as the ability to earn generous cash back (Note: there is a 3% balance transfer fee). You’ll get 6% cash back at US supermarkets (on up to $6,000 in purchases annually), 3% at U.S. gas stations and select US department stores like JCP, Sears, Kohls and Macys, and 1% on everything else. Plus you’ll earn a $150 bonus after spending $1,000 in the first 3 months, an effective 15% back on the first $1,000 you spend. The card does have a $75 annual fee, but if you spend a decent amount on groceries and gas each month it might be the right choice for you. If the annual fee makes you hesitate take a look at it’s sister card the Blue Cash Everyday from American Express which has $0 annual fee, cash back rewards and a 15-month 0% APR period.

Discover it Card – Balance Transfer
Another strong card combining cash back with a 0% intro APR is Discover it Card – Balance Transfer. You’ll enjoy an 18-month 0% intro APR period on balance transfers and purchases, a low ongoing APR after the intro period is over and no annual fee. Additionally you’ll earn 5% cash back in categories that rotate quarterly (on up to $1,500 in purchases) and 1% back on all other purchases. Discover will also very generouslydouble your first year earnings, meaning if you earn $200 in  year one they’ll give you $200 for a total of $400. Even though this is only given in the first year, it’s a pretty darn great bonus! Plus you’ll get your TransUnion FICO Score for free each month, helping you to keep an eye on your TransUnion credit history. The card has a 3% balance transfer fee, but depending on your situation it might still be a good decision.

Disclaimer: This content is not provided or commissioned by the credit card issuer. Opinions expressed here are author’s alone, not those of the credit card issuer, and have not been reviewed, approved or otherwise endorsed by the credit card issuer. This content was accurate at the time of this post, but card terms and conditions may change at any time. This site may be compensated through the credit card issuer Affiliate Program.