Hi Meadowlark -
I'm not sure, since I don't like beans anyway. Here's a link to the atkins website that outlines the kinds of things to add during phase 2. However, it's not an extensive list, so maybe if you're super vigalent about counting your carbs and keeping them spaced throught the day, then it's ok. Hmmmmmm.......
http://atkins.com/Archive/2001/12/15-61563.html
I also searched the recipe section for recipes with beans in them. I don't see any that contain beans (other than green or string beans) until stage 3.
Checking the carb counter, pinto beans are 11 grams per 1/2 cup.