Well, this is complicated, but it helps if you know the rules.
First, remember that at retirement, everything comes out taxed as ordinary income. So basically it doesn’t matter how long you have held a stock or fund inside the plan.
As for the 40l(k), if you are happy with the investments you can leave the money there. Or you can do a direct rollover to Fidelity or Vanguard, and choose from their mutual funds for your investments. By retirement age, you should definitely roll over so you have a wider choice of conservative investments and can put a portion into a money market fund for safety and for liquidity to do required minimum distributions when you reach age 72.
Now your current employer403(b) plan is a different story. I’m assumng it is a company-sponsored plan, and not a union plan.
If they stop offering any plan, then you should immediately do a rollover of your existing assets into an IRA — using the instructions above. Your HR department will help you do that. Or they will advise you of your investment options if they continue to maintain the plan, while not contributing to it in the future. (In general, I’d suggest a rollover.)
If you want to keep contributing to a retirement plan, then you should also open a separate IRA — perhaps at a different firm to tell them apart — and you can contribute $6,000 a year or $7,000 if you are 60 or older.
That advice applies if you love your job. But if you look around, you might find a job at a company that does have a retirement plan and even matches your plan contributions. However, in these uncertain times, I can understand why you would not want to rock the boat on the job front!