When should I stop paying for my term life insurance policy? 

You stop paying for your term life coverage when you decide that you no longer need the life insurance protection and wish to stop it. 

You can either choose to provide written notice of cancelation to your life insurance company, which would help you to get any unused premiums refunded. Or, you can just let your life insurance policy lapse by discontinuing the premium payments.

You may want to stop paying for your term life insurance when the premium goes up at the end of your term life policy term.

From that point on your premiums will increase quite a bit each year you continue to renew your term life policy.

If you need life insurance at that time, and you are still healthy, you may want to compare plans and rates for a new term life insurance policy and see if you can get a better deal elsewhere.