You are going to format each act of the dramatic series in normal spec screenplay format. This means that the meat of the teleplay is going to look just like a normal feature film script.
Each section needs to be identified and labeled, with the first act being titled ACT ONE and starting on a completely new page from the teaser. At the end of an act you identify the act number, with a marker like END OF ACT TWO. You also identify the TEASER and TAG if you like, though it is not always necessary and may make you look as though you are a newcomer. Make sure to start the script with a full title page that identifies just the name of the show and the episode name.
For example:
LAW & ORDER: SPECIAL VICTIMS UNIT
“INFANT CASUALTY”
Keep the text centered and you may opt to use a by line below this if you do not have a way of indicating your credits ahead of time. Try to keep two lines in between the show title and the episode title.