THE SENATE HAS taken a big step toward putting the State Retirement System on a firm financial footing, passing a bill that unifies responsibility for the system, allows for a more aggressive investment strategy and pays for benefits that lawmakers had added without funding.

But the legislation fails to provide a long-term solution to the immediate problem that has forced lawmakers to come to terms with their irresponsible expansions of the pension system — the all-but-guaranteed annual cost-of-living increases for retirees.

Legislators are overhauling the pension system because increased lifespans have combined with the unfunded 28-year early retirement and TERI programs to stretch the Retirement System to the point that it can’t offer COLAs this summer unless lawmakers overhaul it or pump tax money into it. The prospect of no COLAs is so frightening to legislators that they are finally making some difficult decisions to avoid that.

The Senate bill likely does enough to allow the increased payments to be made on schedule — this year. But it doesn’t change the basic problem: We treat COLAs like guaranteed benefits, but we don’t actually put the guarantee into writing, and so we don’t make sure the money is available to pay for them. Unless legislators prohibit COLAs or else provide for them in law, we’ll be back in this position again in a few years.

A House subcommittee voted last week to guarantee a 1 percent COLA each year; it also would allow partial COLAs to be granted when there isn’t enough money to fully adjust pensions to inflation. The panel proposed to pay for the 1 percent increase by requiring employees to pay more into the system, as the State Employees Association offered and the Senate inexplicably ignored, and by increasing employer contributions. But higher employer contributions means there will be less money available to run the Highway Patrol and the prisons and the schools and the rest of the government. And that doesn’t seem sensible right now.

The House panel also proposed to let employers fire TERI employees at will. It’s not a perfect solution, but that change — combined with a provision in both the bills that allows employees who retire and then go back to work for the state to draw their full retirement pay, no matter how much they make — would make TERI so unattractive that few people would participate. That’s good, because there is no justification for the program, which essentially pays employees a premium for their final years at work, whether their supervisors think they deserve it or not.

But both bills also force retirees who take advantage of the extra benefits of the 28-year-retirement option or the TERI program to pay for them. That’s fine for new retirees, but the requirement would apply to people who have already made an irrevocable choice to join TERI. That’s asking for a lawsuit that the state might well lose. More important, it’s not fair. It’s not state employees’ fault that the Legislature passed a bad law; those who have already changed their life plans to take advantage of it shouldn’t have to pay to fix it.

That provision and a few others need to go. But the ingredients for a good fix — smart administrative changes, a system to make the TERI and 28-year-retirement programs pay for themselves, increased employee contributions and a responsible way to address annual COLAs — are now on the table. If legislators merely mix them appropriately, they will go a long way toward redeeming their earlier bad decisions.