Investors are not getting much warning about the magnitude of assets and liabilities that will soon hit corporate balance sheets as companies prepare to implement a new accounting standard on leasing.

A recent analysis by PwC says 37 percent of companies in the S&P 500 disclosed nothing in their annual or quarterly filings during April and early May about how they will be affected by the new lease accounting rules or said they were still evaluating the impact. Another 24 percent provided some qualitative disclosures about the expected effect but provided no hard data.

The analysis found 34 percent of companies are telling investors the adoption of the new rules bringing leased assets and liabilities out of footnotes and into the body of financial statements will have a material effect on their financial positions. Only 5 percent said the adoption of the new accounting will not have a material effect. An earlier analysis of the top 100 lessees among public companies shows most of those companies are at least reporting the adoption will be material. Other polls have suggested companies are behind in their adoption efforts.

The new standard on lease accounting takes effect for public companies on Jan. 1, 2019. Private companies have a more extended adoption timeline, so the rules take effect for them on Jan. 1, 2020.

Companies are required under Staff Accounting Bulletin No. 74 to give investors some advance notice about the pending adoption of new accounting and how it might affect the company’s financial statements. Especially as companies worked through even bigger changes to adopt revenue recognition in 2018, the Securities and Exchange Commission reminded companies often to pay close attention to their SAB 74 disclosures and assure they provide incrementally more information as companies proceed through implementation and get more clarity about what is to come.

In addition to disclosure about lease accounting, PwC also tallied SAB 74 disclosures with respect to another pending accounting change focused on how to reflect credit losses in financial statements. That standard takes effect for public companies beginning Jan. 1, 2020.

PwC says only 1 percent of companies in the S&P 500 have told investors the standard will have a material impact on financial statements, and 7 percent have said the impact will not be material. Only 7 percent have given at least some qualitative disclosure about how that standard will affect the company, and 85 percent disclosed nothing or said they were still evaluating.

The new standard on credit losses requires companies to take a more forward-looking approach to reflecting troubled debt instruments in financial statements, following a “current expected credit losses” model. Under CECL, companies will be required to use both their own historical data and market data to arrive at some projections about where they will suffer losses on their debt-related instruments and book losses even at the inception of those instruments.