"With the significant and ongoing changes in our industry we must continue to transform our company into one that is leaner more nimble and more innately multi-platform," wrote Lang in a memo to employees.
The memo, a copy of which was obtained by Reuters, disclosed the number of jobs affected on Wednesday.
The cuts will occur across the company -- throughout both business division and newsrooms. In addition to its namesake weekly newsmagazine, Time Inc's publications include Sports Illustrated and People.
Lang called the reductions "painful " but said they were necessary in order "to create room for critical investments and new initiatives."
The staff cuts had been widely expected, though they are not as deep as the last round in 2008, when Time Inc slashed 600 jobs in response to the economic downturn.
Parent company Time Warner Inc in November reported that third-quarter revenue at Time Inc fell 6% to $838 million because of declines in subscription and advertising revenue.
Time Warner is due to report fourth-quarter results next week.