Additional contributions are allowed, but not after the maturity date.
There is instant access to funds at each maturity date.
This only came to light far later once the maturity dates were reached.
However some such instruments may have no fixed maturity date.
In fact, maturity dates are currently much earlier than 25 years.
The securities have a 5.02-year average life and an expected final maturity date of June 15, 1998.
Every bill has a specified maturity date, which is when you receive money back.
An American callable can be called at any time until the maturity date.
That is about 72 basis points above Treasury notes with a similar maturity date.
For the remaining $500 million of bonds, the maturity date is April 1, 1991.