Dependent will be 26 years old on May 26th,2015 how long does it take to enroll him.
In other words should I start in April or what is the latest date in May.
I understand he is covered under my policy until the last day of his birthday month but I do not know how much time I need to get started with enrollment.
They should enroll before the 15th of the month before the month they want coverage to start. Losing coverage on a family plan triggers a 120 day special enrollment period starting 60 days before they lose coverage.
Example: Plan Ends April 1st, enroll no later than March 15th. Remember the plan doesn't start until the first premium is paid.
It's important to note, that for a child who turns 26 to be eligible for cost assistance they must file as single. In a case where someone turns 26 mid-year, they can plan to file independently for the months after they turn 26 (a mid-year change in filing status, same thing in cases of divorce).
At 26 there are lots of tax related reasons for a child to file as single, especially if they have their own income above the Federal Poverty Line. In state's that expanded Medicaid, their income can be lower and still qualify them for free or low-cost health coverage.