My wife submitted her social security application on Nov 22nd and it was approved on January 25th. Her January payment will be issued on Feb 9th. Will she receive a retro payment for December?

Hi. I can't answer that without knowing your mother's birthdate, the type of benefit she applied for (e.g. retirement, survivor), and the month she chose to start her benefits, . If your mother was eligible for benefits for December and if she asked to start her benefits effective with that month, then yes she should receive a payment for December. But, if she asked to start her benefits effective with January or if she wasn't eligible for benefits for December, then she won't be paid for December.

Best, Jerry