Last summer, Bloomberg's revelation that JPMorgan Chase (NYSE:JPM) received a de facto taxpayer subsidy of $14 billion made tongues wag for a time, but the subject eventually faded into the background. Of course, the Bank of Dimon wasn't the only bank receiving a helping hand with its borrowing costs, but Jamie Dimon's appearance in Washington to answer questions regarding the London Whale trading debacle naturally put his bank in the spotlight.

This year, the update on this issue has come out before the advent of spring, and the numbers have climbed a bit. Whereas last year's news reflected a total subsidy, as of 2009, of approximately $76 billion for the 18 largest U.S. banks, the most recent article has bumped that amount up to around $83 billion. It is estimated that JPMorgan's cut has risen to over $17 billion.

Five largest banks get the most gravy, but do they need it?
Bloomberg notes that, of that $83 billion, the top five banks gobble up about $64 billion. Besides JPMorgan, Bank of America (NYSE:BAC), Citigroup (NYSE:C), Wells Fargo (NYSE:WFC), and Goldman Sachs (NYSE:GS) all get a sizable chunk of taxpayer charity.

The article explains that the subsidy is an implicit part of the TBTF landscape, whereby these large institutions are considered so systemically important that they must be pampered like toddlers lest they topple and take the whole economy with them. We've already been there, of course, and this seems to be the way the big banks' supposedly fragile ecosystem is being handled since the financial crisis.

This subsidy isn't direct, but it comes about as banks receive extremely favorable financing terms because creditors assume they will be rescued if anything goes awry. Still, it's a lot, and it makes you wonder whether these banks really need this much support. Unfortunately, it appears they do.

B of A and Citi: negative profit without the subsidy
From Bloomberg's calculations, which were annualized over 10 years, JPMorgan would make a small profit without the subsidy, as would Goldman. B of A and Citi, though, would be in negative profit territory if the subsidy was taken away. Only Wells Fargo would produce a somewhat decent return without the additional backup.

What would happen to Bank of America and Citi if this goody bag was suddenly unavailable? Normally, I wouldn't count on anything being done on this score, but Ben Bernanke's appearance before the Senate Banking Committee last week might have lit a match under this issue.

When the Fed Chair was asked by freshman Senator Elizabeth Warren whether or not banks should be paying for this subsidy, he responded that banking reforms are attempting to change the need for such a helping hand. Also, when pressed, he said he believed the subsidy should end.

Nothing may happen, at least for a while -- but each time this subject comes up, it gets a little more oomph behind it. It looks like B of A and Citi had better get going on the mortgage-lending biz, or both may find themselves with very irate investors in the not-too-distant future. 

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.