The $78.4bn the Fed is remitting is also a record, and is $31bn more than a year earlier. In 2009 the Fed had net income of $53.4bn.
The Fed's portfolio has ballooned to $2.16trn, roughly triple its size before the financial crisis, as it purchased securities including US government debt and mortgage-linked bonds in a move to drive down borrowing costs and stimulate the economy.
"The increase was due primarily to increased interest income earned on securities holdings during 2010," the US central bank said in releasing preliminary unaudited results.
Audited results will be issued in the spring and may show some changes, Fed officials indicated.
After driving overnight interest rates close to zero per cent in December 2008, the Fed bought $1.7trn of longer-term Treasury and mortgage-related bonds as a supplement to its pledge to keep overnight rates near zero for a long time.
It followed that up late last year with a new $600bn bond-buying programme, again intended to spur growth by pumping liquidity into the economy. That programme ends mid-year.
The Fed turns over profits to the Treasury annually and has never posted a loss.