It means, you still have your life insurance coverage "In Force".
The grace period is a very useful feature, whose inclusion in every life insurance policy is mandated by every single state in the USA.
The Minimum Grace Period varies from 28-31 days depending on individual state laws, but some life insurance carriers may give longer grace periods.
The grace period officially begins the day the missed premium payment is due, and ends at the close of business after the prescribed number of days have passed.
Learn more about how a life insurance grace period works.