What Age Are Children Covered Under Health Insurance? 
Children can be covered under an existing health insurance plan the moment they are born . Dependent children can stay on a parent 's health plan until age 26 . Many children in America are covered under their State 's Medicaid -LRB- or comparable -RRB- program due to financial constraints of the family . However , everyone has the right to purchase coverage on of off exchange as long as they have the means to pay for it . Having just had a baby girl only 2 months ago our Daughter was immediately put on to our group health plan through my Wife 's employer and we had 30 days to decide whether we wanted to pay the additional premium and add her . 