After a year of holding back on new hires, companies from tech and transportation to defense now say they need more people to work alongside AI. America's biggest companies say they might need more people after all. For months, major employers treated hiring as an expensive last resort. Now, a shift is emerging across industries. Companies ranging from railroad giant CSX to Google parent Alphabet have told investors in recent days that they plan to hire to meet growth goals or to seize on emerging technologies.

The push to expand head count, at least modestly, is a reversal from the prevailing corporate messaging during much of the AI era. Major employers largely held back on adding people due to economic uncertainties or a belief that artificial intelligence could shoulder more tasks on the job. But some executives say the costs and limitations of AI now demand that more people be added; others want to hire people back following layoffs.

"We actually need to accelerate hiring a bit. We're a little bit behind right now," Booz Allen Hamilton's Chief Operating Officer Kristine Martin Anderson told investors Friday. "We're addressing that now."