The new policy was revealed in emails that were widely circulated on social media.
Tesla declined to comment on the messages, one of which appeared to be addressed to executives.
When asked about the policy, Mr Musk said on Twitter that those who do not want to follow the new rules can “pretend to work somewhere else.”
“Everyone at Tesla is required to spend a minimum of 40 hours in the office per week,” he wrote in one of the emails. “If you don’t show up, we will assume you have resigned.”
Mr Musk also stated that he would personally review any requests for policy exemptions.
Mr Musk stated that the company expects its factory employees to work full-time in the office and that in-person collaboration is critical to the company’s success.
“Of course, there are companies that do not require this, but when was the last time they shipped a fantastic new product? It’s been a long time, “He stated this in one of two emails that were leaked and shared on social media.
“Tesla has and will create and actually manufacture the most exciting and meaningful products of any company on Earth. This will not happen by phoning it in.”
Many industries are debating whether to continue the remote work practises that exploded during the coronavirus pandemic.
Some industries, such as banking, have indicated that they expect employees to return to the office, while others, particularly in the technology sector, have stated that they will allow remote work indefinitely. Many places have chosen a hybrid approach.
According to Kastle, which operates security card access systems in thousands of buildings across the country, office occupancy in the United States is around 43 percent.