Tesla's first-quarter delivery numbers indicate the company has some tough times ahead of it.

Now that the electric car maker has missed investor expectations by a rather wide margin, it will be difficult for Tesla to meet its delivery targets for the rest of the year, say investors and analysts who follow the company. The company delivered just over 63,000 vehicles, far lower than the 76,000 analysts surveyed by FactSet had expected.

Tesla shares briefly fell more than 10% Thursday morning. The stock has fallen 12% since the beginning of the year, as Tesla has been dogged by questions surrounding demand for its Model 3 sedan and CEO Elon Musk's legal troubles.

The company did reiterate its annual delivery guidance of 360,000 to 400,000 vehicles, but hitting that target looks more difficult, said Gene Munster, who is founder of venture capital firm Loup Ventures.

"It essentially implies a run rate of 99,000 vehicles per quarter," Munster said. "Now, they did do 91 in the December quarter, but again 63 in the most recent quarter. And I think what that sets this up for is that they probably are going to miss that number."

Hitting its targets will be particularly difficult as federal tax credits for Tesla buyers continue to dry up as the program continues to be phased out this year, said CFRA analyst Garrett Nelson.

"The massive 31% sequential drop in deliveries has negative implications for Tesla's cost of sales per vehicle," Nelson said. "We know they've been lowering prices and ramping up [higher-cost] exports in order to prop up sales volume, all of which should equate to a pretty ugly quarter from a margin perspective."