It may be a good time to check your US passport’s expiration date, because the US Department of State sees a tsunami (my word) of applications coming in 2017.
According to the US State Department (via The Washington Post):
After implementing the Western Hemisphere Travel Initiative, requiring a passport for air travel to and from Canada, Mexico and the Caribbean, the State Department experienced a rush of applications, from 12.1 million in 2006 to 18.6 million the following year.
To put it a different way, the State Department saw a roughly 50% increase in demand for passports.
Of course, if you want to travel to or from Canada, Mexico or the Caribbean, including Bermuda (include out and about in Bermuda), you can also use a Passport Card, however those, like Passports, are only good for 10 years for adults.
Further, as Rapid Travel Chai reported last year, you can no longer have additional pages added to your passport. So if your passport has validity until 2020 but you are running low on pages, then you might also want to consider renewing sooner rather than later. When you do renew, you can request a 52 page passport, to allow for extra room from all of the visa stamps you’ll acquire.