evidence: President Joe Biden’s tax proposal eliminates the "stepped-up basis" on property transferred at death, a move that "reverses a century of tax law" and would have "far-reaching ramifications for investors," according to Andy Friedman, founder and principal of The Washington Update. [...] Repealing stepped-up basis presents challenges. "Recognition of gain on gifted assets imposes a tax before the donor has the sales proceeds to pay," Friedman said. "And determining a decedent’s basis in assets acquired potentially generations ago can be difficult, especially for assets that are not readily traded, such as partnership interests, real estate, art, cryptocurrencies and collectibles." Some Democratic lawmakers are raising concerns about Biden’s plan to repeal stepped-up basis, Friedman said. Even Sen. Bernie Sanders, I-Vt., who has floated legislation to reduce the estate tax exemption to $3.5 million and the gift tax exemption to $1 million, retains stepped-up basis, except for transfers in trust, in his bill, Friedman points out.