McDonald's is making big changes.

It's launching mobile order-and-pay technology and curbside delivery in the fourth quarter of the year at all 14,000 of its US restaurants.

That means that by the end of the year McDonald's customers will be able to order and pay for their food on their smartphones.

The company announced the change at an investor meeting on Wednesday.

If customers choose curbside pickup, they can skip the drive-thru line and a McDonald's employee will bring their food to their car.

This represents a massive shift for McDonald's. More than 70% of the fast-food chain's orders come through the drive-thru. Many of those orders could end up shifting to curbside pickup.

"In the 1970s, McDonald's revolutionized convenience in the drive-thru to make getting high-quality food easy," the company said in a press release. "Now, that experience is being transformed once again."

If executed successfully, the change could result in shorter drive-thru lines. The strategy could also end up requiring extra staffing for the curbside deliveries.