My husband quite his job and I elected to go on COBRA (he did not). My 18 months is up in April. I am pregnant and due in May. I am in Arizona and have no options to cover my maternity after cobra expires. If we file for a legal separation, will I be able to extend COBRA for 18 more months (3 years total) for the baby and I?

Would the legal separation have to be completed before may?

Arizona recognizes legal separation. At least one party must be a resident of the state and both parties must agree to the legal separation, otherwise the court shall direct that the pleadings be amended to seek a dissolution of the marriage. [Based on Arizona Revised Statutes; Chapters 25, Title 313 and 317]

http://www.cobrahealth.com/Divorce.htm

Not only does the term "legal separation" vary by state to state, some state's don't define it at all!

Arizona recognizes legal separation. At least one party must be a resident of the state and both parties must agree to the legal separation, otherwise the court shall direct that the pleadings be amended to seek a dissolution of the marriage. [Based on Arizona Revised Statutes; Chapters 25, Title 313 and 317]

If a court provides approved legal separation papers, COBRA administrators will often accept this as a "qualifying event" for discontinuing spousal health coverage.

However, you are already on COBRA. They might extend your COBRA coverage. Contact your health plan administrator directly and ask them what the plan rules are.

If they will not let you extend your coverage, you can always convert the policy
at the very end, or get a certificate of creditable coverage.