The automaker, founded in 2003, posted its fourth-quarter production and delivery report on Saturday, saying it produced nearly half-a-million vehicles in 2020, representing a 36% increase in sales in 2020.
"So proud of the Tesla team for achieving this major milestone!" Musk tweeted Saturday in response to the electric automaker's report. "At the start of Tesla, I thought we had (optimistically) a 10% chance of surviving at all."
Musk set a goal of delivering 500,000 vehicles in 2020 before the coronavirus pandemic hit, and Tesla stuck to that goal even though the virus forced its only U.S. assembly plant to close for several weeks in the spring.
Tesla also announced its Shanghai factory has begun producing Model Y vehicles, and deliveries are "expected to begin shortly."
In the fourth quarter, Tesla delivered nearly 19,000 Model S/X vehicles and more than 161,000 Model 3/Y vehicles. In 2020, the automaker produced nearly 510,000 total vehicles, including nearly 55 Model S/X vehicles and about 455,000 Model 3/Y vehicles. In total, Tesla delivered 499,550 cars.
In the first nine months of the year, Tesla reported that it delivered just over 318,000 vehicles worldwide, including a record 139,300 in the third quarter. To reach a half million, Tesla would have had to shatter the record and deliver 181,650 vehicles from October through December.
The company's Fremont, Calif., plant stopped production of its Model S and X vehicles between Dec. 24 and Jan. 11, meaning most of the demand was for the Model 3 small car and Model Y small SUV.
It appeared the company was getting close to 500,000 in December but needed a boost to make the number. On Tuesday, Musk tried to juice sales, tweeting that all Tesla cars delivered during the last three days of the year would get three months of the company’s “full self-driving” option for free.
It costs $10,000 to buy the self-driving option. Selected customers are testing the self-driving software on public roads but are still responsible for driving the vehicles, which Tesla has said cannot drive themselves.
Tesla shares rose more than 700% in 2020 to close Dec. 31 at $705.67.
The Associated Press contributed to this report.