NASHVILLE (AP) - State Treasurer David Lillard says he's proposing legislation to reform Tennessee's retirement plan for public employees to ensure its longevity.

Lillard held a news conference on Monday to announce the changes that will apply to state employees, higher education officials and teachers hired after July 1, 2014.

He said the state's plan is currently performing better than those in most other states, but he said its earnings have fallen short of expectations over the last several years and he's concerned about its future.

The changes he's proposing would limit the state's future liability for pension costs by creating a type of hybrid defined benefit-defined contribution plan.

Currently, only teachers contribute 5 percent of their salary. The new proposal requires all employees to contribute that amount.