Supplemental Security Income benefits are split into two categories, being adult/child (2019 = $771), and couples (2019 = $1,157). 

FUN FACT: Couples oddly enough actually have reduced benefits (771+771=1542...wth, so why only $1,157), hence why many dual SSI receipient couples don't get married, so that they may act independently under the law, and receive the full amount of disability benefits.  In other words, the public policy should be to get married, have children and raise beautiful smart babies.  Instead the government attempts to financially restrict disabled SSI couples by reducing their benefits by $385.00 per month.  Does not sound fair right.  Yeah, it is not, but who said life was.

You will see in the following supplemental security income chart, that each year, the amount of benefits go up.  This is because of cola, not coca cola.  Cola is the cost of living adjustment, being how much it costs to live in America.  Think of it this way, the cost of a gallon of milk goes up, and so does the SSI monthly payment amount each year.  For this reason, it started at $157.70 per adult, and now in 2019, it is $771.00.  Notice how in 1979 they leveled out the amount so that there are no amounts in the change category, being 20, 40 or 80 cents.  Ever since then, it has been a dollar amount.  This is for a multitude of reasons; however, it's mostly easier to calculate benefits for the Government when you don't need to consider the pennies.