Event
Clock starts
What to have ready
Lost job coverageMuch the most common
The last day of the old plan — not your last day at work, which is often earlier.
A letter showing coverage ended and on what date. Quitting counts as much as being let go. Losing it because you stopped paying the premium generally does not.
Moved
The date you moved.
Proof of the new address and of coverage before the move. A move only counts if it changes the plans available to you — which, between counties in our states, it often does.
Married
The date of the marriage.
The certificate. Worth doing properly rather than quickly — combining two households changes the income figure and the credit, sometimes considerably.
New baby
The date of birth, adoption or placement.
Coverage can usually be backdated to the date itself, so the child is covered from day one. Check CHIP at the same time — a new child often qualifies when the parents do not.
The list of qualifying events is longer than the common four, and several have conditions that are easy to read past. People talk themselves out of a window they were entitled to more often than they try for one they were not.