Remember that $787 billion stimulus bill? It really cost $836 billion.

The Congressional Budget Office reported Friday that the economic stimulus bill will end up increasing the national debt by $836 billion by 2019, not the $787 billion that CBO first estimated.

The nearly $50 billion difference was reported in CBO's latest assessment of the stimulus, formally called the American Recovery and Reinvestment Act, or ARRA.

The Congressional Budget Office said Friday that it's initial estimate for the cost of the stimulus bill in 2009 was off by about $50 billion.

The report also estimated how much the stimulus bill affected the economy in 2014, but generally found it had a negligible impact, as most of the spending took place in the first few years after it was passed.

For example, it said the stimulus bill increased national GDP by 0.2 percent at most, and lowered the unemployment rate by about the same amount. At most, CBO said, the stimulus bill increased the number of people employed by 300,000.

"The effects of ARRA on output peaked in the first half of 2010 and have since diminished," CBO said.

As of Thursday, the national debt was $18.14 trillion.