Change withholding or decrease payout?

[pamc13]

I receive a monthly payout from a government agency I retired from and also a Social Security payment. My budget is less than the total of these payments. Currently I have funds deducted monthly from my SS payment to put into a money market account. I was wondering if I should decrease the amount paid by the government agency or ask them to change the withholding amount. 

[IrmaN]

@pamc13 

Here is a useful tool that can help calculate your withholdings on your income free W-4 Calculator

Hope this helps