Yes, although there are colleges where the NPCs are not very good, so that the best estimate for those colleges may not be a good estimate.
The NPC would still be the best estimate, because any other means of getting an estimate will be worse. However, this could mean that the best estimate (from the NPC) is still not a very good estimate, so you would be applying almost blindly at that college.
With divorced parents and a college that requires both of their financials, follow the college’s instructions for that situation. If there are no instructions, be sure to include both of their income and assets in the NPC if you want to have any possibility of the result being close.