Every 5,000 miles. Your maintenance required light will come on, don't freak out because it's supposed to do that. It will show up I think 100 miles before you've reached 5,000 miles.
The Maint Reqd light will flash a few times on start-up when you reach 4500 miles from your last change. It will flash more times as you get closer to 5000, then stay on once you reach 5000 until you get it serviced or shut if off yourself and ignore it until the next change. (Not promoting that: BAD, BAD idea. NEvER ignore an oil change!:boxing

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If you do the oil change yourself, you'll have to reset the light yourself, or if the place where you get it done doesn't reset it, you'll have to do that yourself as well. Not sure how to do that, but it's on here somewhere....
You WILL want that light reset. It will help to remind you when the next oil change is due.