IBM has been suspended from gaining business from US federal agencies, pending the results of a probe into dealings with the Environmental Protection Agency. 

To this end, IBM and some employees have been subpoenaed to appear before a federal grand jury.
The case apparently relates to concersn about potential activities involving procurement at the EPA.
The ban by other agencies is a reciprocal agreement that all federal agencies have with one another.
It shouldn't affect the approximately $1,3-billion in work that IBM is currently carrying out for the federal government.