Long-term disability insurance policies typically contain pre-existing conditions clauses. It is common to see wording which specifies that any disability arising within the first 12 months of coverage is excluded if it resulted from a sickness or injury that the employee had been treated for within 90 days prior to the effective date.
With group and employee benefits plans, members who go on leave and stop contributing to premiums are often treated as new employees upon returning in that the pre-existing conditions clause is reset.
Recently, major Canadian insurers have stopped applying the pre-existing conditions clauses with women returning to work from maternity leave. Previously, any care received by the employee (including prescription medications) for a medical condition/illness during the 90 days before returning to work, would preclude coverage for the condition/illness upon re-enrolment in the benefits plan.
Currently, seven major insurers (Co-operators Group Ltd., Desjardins Insurance, Empire Life Insurance Co., iA Financial Group, Manulife Financial Corp., RBC Insurance and Sun Life) have moved towards the approach that employees should retain the same benefits after they return from maternity leave as they had before. It is expected that more insurers will follow suit.
Source: "Mat leave returners no longer facing reset of LTD pre-existing clause" by Kelsey Rolfe of Benefits Canada on January 8, 2020.