The answer depends on your specific circumstances. The following are some factors that might influence you to buy separate student insurance:
Your child is nearing the age at which he or she can no longer be covered under your plan. This is usually around the age of 24 years however do check with your insurance company to find out the specific age limits for your current policy.
The cost savings of removing your child from your insurance plan is greater than the cost of the separate Student insurance plan. To determine if this is the case, get a quote on this website for a Student plan for your child, and then compare that to the cost savings of removing your child from your standard medical plan (you may need to contact your insurance company to determine this amount).
The HMO or PPO network for your insurance plan does not have physician or hospital coverage in the area around your child’s college.
You might not want a separate Student plan if your child has a pre-existing medical ailment. In most cases, expenses relating to pre-existing conditions will not be covered by the Student plan until the policy has been in effect for 12 months.