When the multibillionaire Michael R. Bloomberg hired an army of staff members for his presidential campaign, he lavished them with salaries that were nearly double what other candidates were paying. His campaign also promised something rivals could not match: job security through the general election, even if he dropped out of the race.

But now, less than a week after Mr. Bloomberg, the former mayor of New York, left the Democratic presidential race — endorsing former Vice President Joseph R. Biden Jr. and pledging to put his vast resources behind him — hundreds of Mr. Bloomberg’s field organizers and regional organizing directors around the country are suddenly without jobs, having received emails on Monday that encouraged them to keep their campaign-issued electronics as a sort of severance payment.

In a series of conference calls on Monday, campaign staff members outside certain battleground states learned that their work had ended and that they would be paid through the end of March, according to seven people who were on such calls. The people spoke on the condition of anonymity, citing nondisclosure agreements they had signed with the campaign, from which they were seeking to be released.

“We sincerely appreciate your commitment and dedication over the past few months!” read an email that the workers received, which was reviewed by The New York Times. “As a token of our appreciation, we are offering you the opportunity to keep your laptop and iPhone.”