(1) This section is subject to the vesting requirements of section 64.

  (2) A qualified participant’s employer shall contribute to the qualified participant’s account in Tier 2 an amount equal to 4% of the qualified participant’s compensation.

  (3) A qualified participant may periodically elect to contribute up to 3% of his or her compensation to his or her Tier 2 account. The qualified participant’s employer shall make an additional contribution to the qualified participant’s Tier 2 account in an amount equal to the contribution made by the qualified participant under this subsection.

  (4) A qualified participant may make contributions in addition to contributions made under subsection (3) to his or her Tier 2 account as permitted by the state treasurer and the internal revenue code. The qualified participant’s employer shall not match contributions made by the qualified participant under this subsection.