The trickle of 401(k) plans offering income-after-retirement options is threatening to turn into a flood, as BlackRock recently announced it would offer a new defined-contribution option that will give participants a guaranteed paycheck during retirement.

BlackRock, the number-one investment manager in the world, made headlines recently when it announced its new LifePath Paycheck, which will provide participants with regular payments similar to pensions. The development comes at a time when many Americans are feeling financially insecure about retirement, and the option of a guaranteed incomed plan has become increasingly popular.

"A top concern among American workers is the fear of running out of money during retirement. And yet the industry has focused on helping people understand they need to save—but not how to manage spending in retirement, even as companies have shifted from defined-benefit to defined-contribution plans," said Anne Ackerley, head of retirement at BlackRock. "With this solution, we're rethinking retirement. And part of that was working across the industry to build something new."