These are the top 14 US companies giving new parents at least 4 months of paid time off

The US and most of its states have no paid parental-leave policy, leaving employers to offer it as a perk.

Years of research have shown such policies have health and career benefits for both parents.

The nonprofit Just Capital is advocating for policies that apply equally to primary and secondary caregivers. It's found large, public companies in the US that offer at least four months for both.

This article is part of Business Insider's ongoing series on Better Capitalism.

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Because the United States is the only developed country without a paid-parental-leave policy, Americans have to rely on their state governments and employers to step up. And while there have been recent developments indicating that more will follow suit, only six states and Washington, DC, have paid family-care policies that can be used for new parents.

This means much of that burden is placed on employers.

The nonprofit Just Capital has highlighted large, public companies that it found are meeting this challenge. These are certainly not the only companies with generous benefits for parents, but they all share a key metric. When assessing the quality of a company's policy, Just considered more highly those that offered the same paid-leave benefit to both mothers and fathers (or primary and secondary caregivers, i.e. if a parent in a couple will be spending more time with the infant). It's common for businesses to offer significantly more paid leave to primary caregivers, with additional time for birth mothers. Just's team advocates for an approach where secondary caregivers are given equal time with their new child.

“While the paid leave landscape may generally be improving, there's a long way to go toward creating equal access to all parents,” Just's director of external engagement Yusuf George wrote on a blog post.

Not only do most Americans want both mothers and fathers to have access to paid parental leave, but there is a wealth of research showing that such policies have physical, emotional, financial, and career benefits.

Read more: If California's new governor can deliver on his proposal to offer 6 months of paid parental leave, it would be the most generous policy in the US

And regardless of whether a mother gave birth, used a surrogate, or adopted, babies' brains go through rapid growth in their first year. A healthy bond with their caregivers during this period has lasting positive effects on their development. Paid leave policies allow parents to develop this bond without having to choose between career and family, and without sacrificing a source of income during a challenging period.

There is still a long way to go before most Americans have access to these benefits, but in the meantime, the following companies are showing what's possible.