Some of America’s best-known companies—names such as AT&T Inc., CVS Health Corp. and Delta Air Lines Inc. —likely will soon have to effectively boost the debt they report on their balance sheets by tens of billions of dollars. The total possible impact for all companies: as much as $2 trillion.

Within a few years, companies may have to add to their books the cost of many leases for real estate, aircraft and other items that aren’t already carried there. U.S. rule makers are set to vote Wednesday on whether to approve in principle long-awaited new rules requiring companies to make that addition, though the move wouldn’t take effect until at least 2018.

If approved, as many observers expect, that change could dramatically boost the reported leverage for retailers, restaurant chains, airlines, package-delivery companies and other companies that use leases heavily. Companies must already disclose their lease obligations, but it is done in the footnotes to their financial statements; they aren’t included in the balance-sheet numbers to which investors pay the most attention.

The proposed move by the Financial Accounting Standards Board could help investors more clearly see the true health of companies that owe a lot of money through lease commitments but currently don’t have to reflect those commitments in their balance-sheet numbers, said FASB Chairman Russell Golden. It “will give investors, lenders and others a more accurate picture of the financial condition of the companies to which they provide capital.”

The change won’t create any new obligations for companies, and it isn’t expected to drastically change companies’ earnings or book value. But it could change some financial ratios, such as return on assets. That is because companies will be adding assets to their balance sheets as well as obligations to reflect the impact of the leases. As assets rise, the return as a percentage of those assets would decline.