SPRINGFIELD, IL - The pension system for thousands of Illinois teachers is officially lowering the forecast of how much money it will make on investments

Instead of assuming an 8.5 percent rate of return, the Teachers' Retirement System will now base its plans and projections on 8 percent growth.

The prediction of less money in the future means the retirement system faces a bigger funding problem. The latest estimate is that TRS has only 42.4 percent of the money it needs for pensions in the decades ahead

The retirement system's executive director says assuming a lower rate of return is the prudent thing for long-term planning.

The change also means the state's annual contribution to the pension fund will increase slightly next year.