Can an adult child claim against a parent's estate in Alberta if they were left out of the will?

This answer covers the law of Alberta.

Only in limited cases. An adult child, 18 or older, is a family member under Part 5 of the Wills and Succession Act only if they are unable to earn a livelihood because of mental or physical disability, or are aged 18 to under 22 and a full-time student who cannot withdraw from the parents' charge. An able-bodied adult child aged 22 or older, or one outside those categories, has no Part 5 claim.

If the child qualifies and the will does not adequately provide for their proper maintenance and support, the Court may, on application, order that any provision it considers adequate be made out of the estate. The Court looks at factors such as the child's relationship with the deceased, age and health, capacity to contribute to their own support, and entitlement to support from another person.

Time is limited: an application must be commenced within 6 months after the grant of probate or administration is issued, but the Court may allow a late application for any part of the estate that has not been distributed as of the date of the application. How a disability benefit or a trust affects a claim is a matter for the Court's discretion, so confirm with a lawyer.