when is open season for tsp contributions?
(2) Second open season rule governs both employer and agency contribu-tions for all employees hired after January 1, 1987 through December 31, 2000. (3) Employees appointed during the period January 1 through June 30, 2001 could elect to contribute during the May 15 through July 31, 2001 open season. (4) Employees appointed on or after July 1, 2001, had a 60-day window to elect to contribute. After the window closed, they reverted to the normal open season rules.