Life insurance is meant to replace income in the event of premature death. It is important that the breadwinner of a family insures their income for as long as their dependents will be relying on it; in some cases this can be 15-20 years. Even stay-at-home parents should be insured.
Premiums tend to increase with age, and waiting to purchase a policy can actually end up costing your more money in the long run. Ideally you will be able to reduce the amount of life insurance you have as you pay off debts and eliminate other financial obligations. If you are still paying off a mortgage, it is essential to ensure that your dependents have a home in the event of tragedy.