(1) Are you vested?
(2) The notification requirement is by the time the plan sponsor files the annual report with the IRS (form 5500) for the plan year following the year of serverance of employment. For example, assume a calendar year plan and that you left on June 1, 1997. Then the plan sponsor must notify you (and the SSA) by the filing of the 5500 for the 1998 plan year, which is generally 7 months after the END of that year. In this example, that could be July 31, 1999. (A 2-1/2 month extension is also permitted and is common.)
Note that the form on which you will actually be listed is not open to public inspection because it will likely contain information about other individuals.