My ex-husband and I were married for 9 years we share custody of our 7 year old son. My husband died recently. Am I eligible to claim a survivor’s benefit for my son on my ex-husband’s Social Security account?

Yes.  Your son will be eligible for a child’s benefit on your late former husband’s Social Security record.  Generally, he will remain eligible for child’s benefits until he reaches age 18 (19 if he is still attending a secondary school at that age).  You should apply with the Social Security Administration on your son’s behalf as soon as possible.  At the same time, you will want to apply to serve as his representative payee. Such an application will enable Social Security to pay your son’s benefits to you on his behalf.