Common law partners are eligible to enrol in a group benefit plan after they've been living with the primary plan member for 12 months.

The partner has 31 days from the 12-month mark to join the plan.

If the partner decides to join the plan after the 31-day window, they will be asked to complete a medical questionnaire and potentially a medical exam. The insurance company may decline to allow the partner to join the plan.

It's therefore recommended to allow the partner to join as soon as they become eligible.