The Terrorism Risk Insurance Act or TRIA, passed after 9/11, requires insurance companies to offer terrorism coverage to their business and commercial clients. However, purchasing that extra protection is optional.

"We understand that about 60 percent of the market is taking up terrorism insurance policies,” says Sean Kevelighan, CEO of Insurance Information Institute.

According to Marsh's 2016 Terrorism Risk Insurance Report, media companies, education, hospitality and healthcare organizations are the most likely to purchase property terrorism insurance.  Companies in the Northeast are far more likely than those in any other region of the country, with businesses headquartered in DC and Massachusetts leading the pack with an 84 percent take up rate.

Jennifer Rubin is the Product Head for War, Terrorism and Political Violence at Hiscox. She says when considering this insurance, companies need to look at the big picture.

"Your business may not be the target but your business could definitely be impacted by something that happens in your city,” Rubin says.

Beyond damage to the structure, the insurance covers loss of income if you are unable to operate your business in the aftermath of an attack. 

And since this is an evolving field, Rubin says Hiscox is developing a new service that will help businesses overcome negative perceptions that might follow even the threat of a malicious act.

The annual premium depends on the size and value of your company from a few thousand a year for a small business to six figures for a major corporation. Rubin says it's just like home or auto insurance.

"Meaning it helps you sleep at night, that you know that you are protected in the event there's an attack and if there's not an attack well, you spent money to sleep better,” she says.

Even though there hasn't been an attack since 9/11 where TRIA was called upon, Sean Kevelighen of the Insurance Information Institute says it's working.  The reassurance offered by terrorism insurance is one the reasons impacted areas - like Lower Manhattan - are able recover.

“I think what you are seeing today is an illustration of the system working,” Kevelighan says. “The economy is thriving - commercially, residentially, tourism - everything is bustling here so I do think the system did work."