As a claims-made policy, errors and omissions insurance covers a claim only if the incident and resulting lawsuit happen while the policy is active. That's why most new businesses purchase an errors and omissions policy early on and maintain the policy for the life of their business.
Maintaining uninterrupted coverage ensures you're protected if long stretches pass between the incident and the resulting lawsuit. Some states have lenient statutes of limitations for these types of suits.
If your business might be exposed to risk now or in the past because you’ve let a prior policy lapse, bring it up with your insurance agent. Options to extend your protection may be available.