American Airlines is giving its AAdvantage program members a new way to spend their miles. Over the coming weeks, eligible members will be able to pay for select flights with a mix of cash and miles on aa.com and in the American app.

The move brings American in line with rivals including Delta Air Lines, United Airlines and Southwest Airlines, which already offer some form of cash and miles bookings. It could be handy if you have a small balance of American miles you can't otherwise use. But American hasn't said what each mile will be worth redeeming them in this new way, and the option wasn't live in our accounts when we tested it.

Related: Combination of points and cash: How I strategize my award redemptions

Once the new option is live, eligible U.S. AAdvantage members will be able to book domestic cash flights on American, excluding flights to and from Alaska and Hawaii, and then choose how many AAdvantage miles they wish to redeem to reduce the cash cost of the flights.

Unlike searching for an award booking, you won't need to select the "Redeem miles" button when searching for a flight, and it won't depend on traditional award availability; instead, you can follow these steps:

American Airlines has not disclosed what redemption value members will receive from using the new option, other than saying that pricing may vary by destination, itinerary and flight, while available cash-and-miles combinations are determined by American and may also depend on the AAdvantage member's mileage balance.

American's example in the screenshot above doesn't show the fare before miles were applied, so we can't calculate the exact value. Based on similar options, such as using miles for Instant Upgrades , we'd expect around 1 cent per mile.

Cash and miles could make sense if you have a small AAdvantage balance. A few thousand miles usually won't cover a full award, let alone an aspirational redemption like business-class travel to Europe or Asia. Putting them toward a cash fare to save, say, $50, is better than leaving them sitting in your account if you don't think you'll ever use them.