5.1.2 types of securities treasury bills: the shortest-term government securities with original maturities of 3 months, 6 months or one year treasury notes: securities with an original maturity of between one year and ten years treasury bonds: which may be issued with any maturity longer than ten years5.1.2 types of securities treasury bills: the shortest-term government securities with original maturities of 3 months, 6 months or one year. treasury notes: securities with an original maturity of between one year and ten years. treasury bonds: which may be issued with any maturity longer than ten years