Tesla Motors CEO Elon Musk was paid just under $70,000 in 2013. But he could be in line for much, much more.

According to a Tesla filing with regulators Thursday, Musk made a base salary of $33,280 in 2013. That was the minimum he was required to make under California law. He got an additional $36,709 in company bonuses.

Tesla says Musk, the billionaire founder of PayPal and rocket-building company SpaceEx, only accepts $1 and returns the rest to the company.

Musk could someday rake in much more from the company he helped found in 2003. Under a compensation package approved in 2012, Musk was awarded options to buy nearly 5.3 million shares of Tesla stock at $31.17 each.

The stock closed Thursday at $207.86, making those shares worth about $900 million.

The plan is supposed to compensate Musk over a 10-year period, but only if the company meets performance goals. Musk can't exercise all the shares, for example, unless Tesla's shares reach a total value of $43.2 billion. The company's shares are currently worth $25.6 billion.

Musk would also have to meet milestones for production of Tesla's planned Model X electric SUV and its Generation Three vehicle, which will cost around $35,000. Right now, Tesla only makes the Model S sedan, which starts at $70,000.

Tesla said in its filing that some incremental stock value goals have been achieved, but the operational milestones, while probable, have not been reached, so none of Musk's shares have vested.