If you once worked for the federal government and then left for greener pastures, you may have taken a refund of your retirement contributions. Now if you’re back working for the government, you’re wondering if it would be a good idea to redeposit that money in order to boost the dollar value of your retirement annuity.

The first thing you’re going to have to do is find out how much you owe. To do that, you need to get an application to make deposit or redeposit from www.opm.gov/forms. (Be sure to get the correct one for your retirement system.) Fill it out and send it to OPM. The address is on the form.

Obviously, the question of whether or not to make a redeposit depends on the financial impact it will have on you. In order to make that assessment, you’ll need to go to your personnel office and have one of the benefits specialists run the numbers for you. They’ll base those calculations on your expected age at retirement and an estimate of how big a deposit you will owe when you retire.