Dear Rusty: My question is about benefits and getting married. I am a retired man, 65-years-old, and collecting Social Security plus two pensions. My girlfriend will turn 62 in October of 2020 and plans to apply for Social Security benefits on her 62 birthday. If we were to get married, would we be affected money wise? Or should we just live together? Contemplating Marriage
Dear Contemplating Marriage: Your own Social Security benefit will not be affected in any way if you get married, unless your potential new bride is a very high earner and her Social Security entitlement at her full retirement age (which is 66 years and 8 months) is more than twice the full benefit amount you were entitled to at your full retirement age (even though you claimed your SS earlier). In that case, you would become eligible for a spousal benefit from your new wife after you are married for one year.
If, however, your potential bride is the lower earner and claims at 62 but is entitled to a Social Security benefit at her full retirement age (FRA) that is less than 50% of your FRA benefit amount, your new wife may be entitled to a "spousal boost" from you after you are married for a year. I cannot tell you the answer to those questions without knowing your respective benefit amounts at each of your full retirement ages.
You may also wish to consider potential survivor benefits. If you are married and one spouse dies, the surviving spouse is entitled to 100% of the amount the deceased spouse was collecting at their death, if the surviving spouse has reached full retirement age (otherwise the survivor benefit is reduced for claiming it early). The surviving spouse gets the survivor benefit if that benefit is more than they are entitled to on their own.
In any case, neither of you would be eligible for a Social Security spousal benefit or survivor benefit from the other unless you are married (you must be married for at least one year to get a spousal benefit and at least 9 months for a survivor benefit).
Note that so-called "common law" marriage isn't recognized in most U.S. states, and Social Security goes by state law on that topic. The only states which currently recognize common law marriage are Colorado, Iowa, Kansas, Montana, New Hampshire, South Carolina, Texas, and Utah (and the District of Columbia). So, unless you were to live in one of those states, or in D.C., cohabitating would not be considered a "marriage" for the purposes of Social Security benefits, and no spousal or survivor benefits would be available to either of you.