Offering employees time off to care for a loved one isn't just nice; it might just be inevitable.

With presidential candidates from both major political parties proposing a federal mandate on paid parental leave, some companies have chosen to get ahead of any potential new regulations. In 2016, 26 percent of employers surveyed by industry nonprofit the Society for Human Resource Management offer paid maternity leave beyond what's covered by short-term disability or state law. Twenty-one percent offer paid paternity leave and 20 percent offer paid adoption leave.

Those looking to gain a hiring and retention advantage with generous paid personal leave programs are already light years ahead of companies that would simply abide by a federal mandate, says Lisa Horn, SHRM's director of congressional affairs. Here's what it takes to get ahead of the curve, courtesy of the programs offered by high-profile companies like Deloitte, Etsy, Facebook, GoDaddy, Netflix, and Nike:

Leave for whom?

While both presidential candidates call for paid leave of some kind after the birth or adoption of a new baby, they differ on exactly who gets it. Donald Trump's platform--supplemented with comments from his daughter Ivanka in an interview with Cosmopolitan magazine--calls for maternity leave for married women who have given birth. His plan does not include husbands or partners of either sex, single women, or couples who adopt.

Hillary Clinton, as well as major companies like Nike, Etsy, and Netflix, advocate for paid time off for both parents, regardless of gender, after the birth or adoption of a child. In addition, others, like Deloitte and GoDaddy, offer paid short-term disability leave for women who have a natural birth or undergo a C-section.

Length of leave

The length of paid leave programs ranges widely. Netflix is one of the most generous, offering unlimited paid time off within the first year of having a new baby, followed by Etsy, which offers six months, and Facebook, which offers four months. At eight weeks, Nike's plan falls in between the lengths suggested by Trump and Clinton (six and 12 weeks, respectively).

For mothers, both candidates' plans call for more time off than the six weeks SHRM found U.S. organizations currently offer on average. The nonprofit says fathers receive just over three weeks of paid paternity leave, and parents who adopt or use a surrogate get roughly five weeks on average. Unlike paid vacation days, very few people left any parental leave unused.

Cost to employers

This is the trickiest part, as paid parental leave programs do not necessarily guarantee employees receive full pay while out of the office. Clinton says she wants to guarantee workers will get at least two-thirds of their wages during time off. Trump's plan says he proposes "partial" pay through the existing unemployment insurance system. Both claim costs would be fully paid for within the federal system, and pose no additional costs to businesses.

Some states and municipalities already offer incentives to businesses that provide paid parental leave--California offers public disability insurance which covers 55 percent of workers' pay for up to six weeks. The city of San Francisco took the law further by requiring employers to cover the remainder of workers' pay for that period.