回复：请问怎样向NIH的officer要推荐信？

I don't think there is a policy for preventing their employees from writing recommendation letters in NIH. I think maybe if people do not want to write a letter for you. They always use this as an excuse. I got two letters from NIH this month. Both of them were printed on offcial letterheads. One is a senior director in NIH. He cited my paper in his review. I never met him. I sent him a message to ask if he can write a letter for me. He answered "Yes".