A second shot at love can seem like a miracle for some retirees. But couples need to remember that remarriage may affect retirement realities such as Social Security, veterans benefits if applicable and pension payments, Speyer says.

For instance, if you are receiving Social Security survivor benefits when you remarry, you may be eligible for a boost based on the record of your new spouse, once you reach age 62 or older.

Meanwhile, don't forget topics such as power of attorney and who makes health care decisions should one spouse become incapacitated. Many times people made a child their designated decision-maker, then forgot to change once they remarried.

And though it may seem counterintuitive at that age, Tom Eddy, general counsel for BPU Investment Management in Pittsburgh, suggests obtaining life insurance as a way to provide for a spouse or child.