A little more than half of the Standard & Poor’s 500 have disclosed something about how they expect to be affected by the new reporting of credit losses when it begins next year, but only a small fraction have determined the potential materiality.

A PwC analysis of annual and quarterly filings through late February finds 44 percent of the S&P 500 that are public companies had so far provided no disclosure about how they’ll be affected by the new accounting, which requires companies to adopt a “current expected credit loss” model to report the state of their debt instruments. Companies are at various stages of implementing Accounting Standards Codification Topic 842, CECL standard, which takes effect Jan. 1, 2020, for calendar-year public companies.

The Securities and Exchange Commission, through its Staff Accounting Bulletin No. 74, requires companies to disclose to investors the expected effect of new accounting pronouncements before they become effective. CECL has been described by some as the most significant change to bank accounting in decades.

PwC says 43 percent of S&P 500 disclosed through late February at least some qualitative information about the pending new accounting, although those companies also told investors the effects of the new standard had not yet been determined. Only 13 percent had determined the effect and were beginning to explain their expectations to investors. Of those, 11 percent said they expected the effect to be immaterial, and 2 percent said they expected the standard to have a material effect on their financial statements.

JPMorgan Chase and Citigroup are among companies that have provided detailed SAB 74 disclosures, with data. JPMorgan said the new accounting will cause the company to increase its allowance for credit loss by $4 billion to $6 billion, and Citigroup said it expects its credit loss reserves to rise by 10 percent to 20 percent.

The Financial Accounting Standards Board recently rejected a bid by a group of banks to reconsider how the CECL reserve will flow through earnings, deeming it overly complex without providing any “incremental improvement” in the accounting. The board also determined it will not require companies to disclose gross writeoffs and gross recoveries by vintage as illustrated in one of its examples within the guidance.

Rep. Blaine Luetkemeyer (R-Mo.) is not letting up on his calls for FASB to delay the effective date of the standard so its effect on the economy as a whole can be better understood. Luetkemeyer has won the support of banks who say the new accounting will dry up lending, especially when the economy is headed for a downtown. The American Bankers Association has asked the U.S. Treasury to intervene, but FASB has so far held its ground.

Luetkemeyer, ranking member of the House Subcommittee on Consumer Protection and Financial Institutions, along with Patrick McHenry (R-N.C.), ranking member of the House Committee on Financial Services, wrote to SEC Chairman Jay Clayton recently imploring him to get involved. They ask Clayton to answer some concerns that have been raised about CECL’s expected effect, including increased reserves and their effect on lending.

The SEC declined to comment on the recent letter.