Actually, that will depend on your age, health and the insurance company.
There are some insurers that offer term life plans for a duration of up to 35 or 40 years.
However, it seems a 40-year term is likely their longest term life policy available.
If you need coverage lasting longer that 40 years, then a permanent life insurance policy may be the type of life insurance plan to consider.
Learn more about the longest term life insurance policy.