I am divorced after 40 years of marriage, age 69, and began receiving social security benefits on my ex-husband's record at my age 66. Early in our marriage I worked in the private sector but barely earned my 40 quarters to be eligible for social security. I returned to teaching and no social security is withdrawn from my earnings. However, since I returned to teaching later in life, I elected to participate in a 401 A (defined contribution program) and not the annuity/pension program. When I decide to retire, will my social security benefit that I am receiving on my husband's record be reduced by the amount in my 401 A, which I plan to rollover into an IRA?
I can't give you a definite yes or no answer, but it sounds like when you start receiving distributions from your defined contribution plan or if you roll the funds over to an IRA, it will probably cause at least part of your divorced spousal benefits to be offset. The reason for that is due to the Government Pension Offset (GPO) provision, which can result in a person's divorced spousal benefits being offset by 2/3rds of the amount of their government pension.
If a person participates in a defined contribution plan in lieu of a pension plan while working for a government employer where their wages are exempt from Social Security taxes, any Social Security auxiliary or survivor benefits may still be subject to GPO when the person becomes entitled to start receiving distributions from the plan. If distributions from the plan are paid in something other than a set monthly rate, or if the participant can control the amount of the distributions, then Social Security uses a proration method to determine the countable monthly amount used for offset purposes (https://secure.ssa.gov/apps10/poms.nsf/lnx/0202608400).