Divorcing: When do ssi benefits go back up for payee?

Here is the procedure from the SSA's Program Operations Manual System (POMS) :

Spouses Separate or Divorce

If an ineligible spouse and eligible spouse separate, or their marriage ends in divorce, the ineligible spouse's income is no longer deemed to determine eligibility effective with the month after the month of separation or divorce. Deemed income in the budget month continues to affect payment if deeming applied in the budget month.

NOTE: If an application is filed in the month of separation or divorce, deeming applies that month even if the application is filed on or after the date of separation or divorce.

https://secure.ssa.gov/poms.NSF/lnx/0501320450

Here's the text from the Code of Federal Regulations :

(2) Spouses separate or divorce. If you separate from your ineligible spouse or your marriage to an ineligible spouse ends by divorce, we do not deem your ineligible spouse's income to you to determine your eligibility for benefits beginning with the first month following the event. If you remain eligible, we determine your benefit amount by following the rule in paragraph (e) of this section provided deeming from your spouse applied in the prior month.

http://www.ssa.gov/OP_Home/cfr20/416/416-1163.htm

I haven't seen a way to estimate how your benefit will change. But here is a link which gives an example of how benefits decrease which addition of deemed income. Your case, of course, would be the opposite of these examples.

http://www.ssa.gov/ssi/text-income-ussi.htm