Which rider permits an insured to purchase additional insurance without proof of insurability?

The Guaranteed Insurability Rider allows an insured individual to purchase additional insurance coverage at specified times without the need to provide proof of insurability. This means that as the insured's needs change—such as marriage, the birth of a child, or other significant life events—they can increase their coverage reliably and without undergoing medical underwriting.

This rider is particularly beneficial for those who may have concerns about their health status changing in the future, as it secures the ability to increase their insurance benefits without the risk of being denied coverage due to health issues that may arise.

The other riders listed, such as the Waiver of Premium Rider, focus on different aspects of insurance protection—like waiving premium payments during periods of disability—rather than providing the opportunity to increase coverage. The Accidental Death Benefit Rider adds benefits in the event of death due to an accident, while the Cost of Living Rider adjusts benefits based on inflation but does not allow for additional purchases of insurance. These features serve distinct purposes within insurance policies, thus highlighting the unique role of the Guaranteed Insurability Rider in providing flexibility for increasing coverage.