The lifespan of the average American is nearly 78 years. However, most live just 66 of those years in good health, according to research from Deloitte's Health and Life Actuarial teams.

"All Americans could potentially live up to 95% of their years in good health and live to be nearly 90 years old," the study found. "Not only can people of all ages gain more years and more healthy years, but we could spend less on health care in the process."

The report distinguishes between lifespan and health span:

• Life span is the average expected number of years between birth and death.
• Health span is the average number of healthy years between birth and death.

Employers can be catalysts in driving the change toward living healthier years and spending less. "The payoff could be sizeable and long-lasting," the report said. "In fact, we could see lifespan in the United States increase by an average of 12 years and health span increase by an average of 19.4 years by 2040, according to our analysis."