According to MarketWatch, the settlements of lawsuits so far with top lenders are paving the way for an additional $16 billion in penalties to be paid by banks including Bank of America (BAC) and Goldman Sachs (GS) over mortgage-backed securities sold to Fannie Mae andFreddie Mac.

Of the banks that have recently settled — including Morgan Stanley last week — the settlement amounts equate to roughly 12% to 13% of original principal balance of securities sold to the GSEs. The remaining banks could expect to pay approximately $16 billion in total if that settlement range holds.

Expect the majority of financial firms to settle this year on billions of dollars from outstanding lawsuits with the government, related to the sale of mortgage-backed securities, sources tell MarketWatch.