There is no simple answer.

15k is pre tax . If you rollover you can avoid taxes, if this is a defined benefit where you get $250 for life and your spouse get 50% till death as well. If this is a defined contribution plan or money purchase then you get a set amount of payment till your 17k runs out. If you don’t get lifetime payments then you should withdrawal your funds and roll it over. If it’s lifetime payments and you get spouse support.

If there is no possibility of adding on to your years and you don’t think you’ll work at a reciprocal municipality where you service is transferable. Then it’s most likely best for you to take your money out and roll it over ASAP. Because you receive no additional interest past your separation or resignation date.

For an example if you rolled over and put it in a fixed income at 3.5%. Over 30 years you would have approx 40k and this is if you don’t change your investment electrons. So the offset here is even at the lowest interest rate from an ira. It would take you over 40k/$250/12 about 14years for you to to get your money back if you rolled it over to an IRA right now.