Ford told dealers Monday that it is suspending customer orders for the Maverick pickup truck because it is already straining to fill a backlog. The company will resume taking orders for the 2023 Maverick in the summer, it said in a memo to dealers, reviewed by The Wall Street Journal.

“We didn’t want to take more orders than we could build,” said Dean Stoneley, general manager of Ford trucks, in an interview. “We’re getting customers who would have perhaps bought a used car and are now buying the Maverick because it is so affordable,” he said.

The strong reception for the Maverick—which starts at about $20,000—comes as car prices soar and auto makers offer fewer entry-level choices, dealers and analysts said.

New-car prices had been outpacing inflation for several years even before pandemic-related supply-chain disruptions sent prices sharply higher. Last year, the average price consumers paid for a new vehicle jumped 13%, to a record $40,457, according to research firm J.D. Power.

Now, with thin dealer inventory from a nagging computer-chip shortage creating a seller’s market, shoppers are struggling more than ever to afford new wheels, data show.

Dealers have had trouble keeping vehicles of any type in stock because of the chip shortage, which has crimped production for the past year. Ford dealers say the Mavericks that arrive on their lots already are earmarked for customers who preordered them.

Shutting off customer orders is unusual, said Chris Lemley, president of Sentry Auto Group, a Boston-area Ford-Lincoln-Mazda dealership. “But it’s appropriate under the circumstances to avoid customer disappointment.”

Most Mavericks are selling in the mid- to high-$20,000 range, Mr. Lemley said. “We desperately needed something in that price range,” he said.

Ford rolled out the Maverick last year as a more-manageable alternative to the big pickups that now dominate the U.S. market. The truck has drawn many first-time truck buyers who migrated from sedans or small SUVs, dealers said.

Ford in 2018 decided to eliminate from its lineup the cars that had long served as entry points for new car buyers, including the Fiesta and Focus, which were money losers, executives have said.

Ford’s move to ditch entry-level cars frustrated many dealers, who said it left them few options to offer shoppers for less than $30,000.

Other car companies have also followed suit in recent years, jettisoning budget small cars and hatchbacks from their showrooms and adding more higher-priced trucks and SUVs to fatten profit margins.

There are five nameplates in the U.S. today with an average sticker price of $20,000 or less, down from 19 a decade ago, research firm Cox Automotive said.

Affordability of new vehicles hit a historic low in December, according to an index from Cox Automotive and Moody’s Analytics. The number of weeks of income needed to purchase a new vehicle hit 43 on average in December, the firms said. The index ranged between 32 and 36 weeks for nearly a decade before it began rising sharply in 2020.

The average monthly payment for a new vehicle also has climbed, up nearly 20% in December from a year earlier, to a record $688, Cox estimates.

Mr. Stoneley declined to say whether the Mexico-built Maverick is profitable but said Ford is able to reduce costs because the truck is built with many common parts from other models, including the Escape and Bronco Sport SUVs.

He added that customers can still buy Mavericks off dealer lots and that Ford will ship some trucks to dealers in coming months in an effort to replenish stocks, but customer orders will be suspended until summer.

Because the Maverick is a new entry that is smaller and cheaper than other pickups in the market, it has been difficult for Ford to forecast demand, Mr. Stoneley said.

J.D. Power expects Ford to sell at least 80,000 Mavericks in the U.S. this year. Research firm AutoPacific forecasts about 95,000 in sales this year and 120,000 in 2023.

In the past two years, Ford has introduced several well-received new models, after allowing its lineup to get stale, dealers and analysts have said.

Buzz around new entries such as the Bronco, the off-roader that recently returned after a quarter-century hiatus, and especially electrics such as the Mustang Mach-E SUV and the forthcoming F-150 Lightning pickup truck has helped drive Ford shares to a 20-year high.

Chris Goeschel, an executive at a Las Vegas Ford dealership, said he has seen strong demand from local business owners, including electricians or pool-maintenance companies, for Maverick models in the mid-$20,000s.

“It’s got a lot more utility than people have come to expect in that price range,” he said.

Write to Mike Colias at Mike.Colias@wsj.com