Maintainance levels of carb intake vary from person to person. Some find that they can maintain at 100 grams of carb per day or more, others find that they need to be closer to 50 or 60 grams.
The important thing is to make sure that the types of carbs that you do choose to eat are low glycemic and as unprocessed as possible; whole grains, whole fruits (not juices), and vegetables.
Since you're not looking to lose more weight, I'd suggest that you start in the range of 45-60 grams of carb per day and see how you do. You can always adjust it up or down as necessary.
Good luck!