Bank of America Corp. and Citigroup Inc. may need more capital to weather a prolonged recession, according to regulators performing “stress tests” on banks, the Associated Press reported.

According to people familiar with the situation, Bank of America could have a shortfall of billions of dollars, even after receiving a $45 billion government bailout. Citigroup also received $45 billion in bailout funding.

The 19 banks that took the government’s “stress test” have until today to rebut the preliminary findings. Already many executives of the largest banks, which account for about half of the U.S. banking system’s loans, are lobbying regulators to raise their scores before numbers are finalized Friday and released to the public on Monday.

Those banks that fall short may need to raise their capital reserves beyond current requirements in case loan losses continue to mount, federal officials said, also stressing that their need to raise capital does not mean their viability is in question. Options include converting the government’s stake in the banks to common shares, raising money from investors or receiving more funds from the Treasury Department’s $700 billion bailout program.

Those banks deemed to have enough capital might be permitted to repay the billions of dollars the government injected into them last fall. Many large banks have expressed interest in repaying the money to escape executive compensation limits and other obligations.