The length of post-employment restrictions depends upon how you were involved in certain kinds of matters – like contracts, grants, or lawsuits – while you worked for the government. If you were personally and substantially involved in the matter, then the restriction is permanent. If you merely supervised others who did the actual work, then the restriction lasts for two years from the date you leave Government service. The two-year restriction does not apply unless you supervised the matter during your last year of Federal service.  If you worked on certain trade or treaty negotiations during your last year of Government service and had access to certain restricted information, you should contact your agency ethics official because you may be barred for one year from aiding or advising anyone (other than the United States ) concerning those negotiations.  

U.S. Office of Government Ethics’ Post-Employment Summary states:

 [18 U.S.C. § 207(a)(1)] is a lifetime restriction that commences upon an employee’s termination from Government service. The target of this provision is the former employee who participates in a matter while employed by the Government and who later “switches sides” by representing another person on the same matter before the United States . The restriction is measured by the duration of the matter in which the former employee participated.  The restriction does not apply unless a former employee communicates to or makes an appearance before the United States on behalf of some other person.