1. Hire leaders

The Hartford's 2014 Millennial Leadership Survey found 83% of millennials consider themselves to be a leader today and 73% aspire to be leaders in the next five years. The workplace is the No. 1 area where they want to lead, with most of their current leadership in their personal lives.

Consider that personal leadership as a great training ground for professional leadership. If you are hiring employees in 2015, I suggest you look for Gen Y candidates with leadership experience outside of work, including in community organizations, school groups and sports teams.

2. Offer training

While they feel like leaders now, millennials recognize that they need training and development to be effective leaders in the workplace. Consider making 2015 the year that you create a leadership succession plan – or refine your existing plan – and offer the training and development necessary to put the plan in action. If you can't offer in-house training, provide millennials with ideas (and ideally funding) for external training resources, such as online classes, local college courses, books and blogs.

3. Create mentors

A reverse mentoring program, in which new and experienced employees mentor one another, is another way that you can help your Gen Y employees become the next generation of leaders. Reverse mentoring allows a company to benefit from the expertise of each generation, such as knowledge transfer from long-time boomer employees and the tech skills of digital native millennials. Reverse mentoring can also provide engagement and networking opportunities to those who may feel ignored, such as Gen X'ers who are stuck in the middle of two massively influential generations.

4. Become flexible

When asked about what an employer could offer to retain young employees, millennials in The Hartford's poll said flexible work schedule (58%); merit-based salary increase every six months (41%); and insurance benefits (38%). Don't we all want those? You will most likely attract and retain employees from all generations if you strive to offer a good work-life balance, fair-market salaries, and benefits that help protect employees' health and wealth.

5. Protect your leaders

Don't forget to protect your employees. Now that you've targeted your future leadership, be sure to offer income protection and communicate the value of this benefit. Employees who have disability insurance return to work after an illness or injury faster than those who do not have the coverage. That faster recovery can help your company with its productivity and can help employees with their personal and professional goals.

The millennial countdown to 2020 is coming. With some planning, you can be ready for it – and even celebrate it.