S. 608 — IRS MATH Act of 2025

This section revises notice requirements under IRC §6213(b)(1) for IRS assessments of mathematical or clerical errors (i.e., errors allowing assessment without a notice of deficiency, with taxpayer abatement rights within 60 days). Specifically, it requires such notices—sent to the taxpayer's last known address—to describe the error in plain language (including type, relevant Code section, nature, and return line); provide an itemized computation of adjustments to specified items (e.g., adjusted gross income, taxable income, deductions, listed credits, taxes, withholdings, payments, refunds, carryforwards); include the automated phone transcript number; and display the abatement request deadline in bold font size 14 immediately next to the taxpayer's address on page 1. It further prohibits notices listing multiple potential errors and applies these changes to notices sent more than 12 months after enactment. The section also requires abatement notices under new §6213(b)(2)(C)—sent to the last known address—to describe the abatement in plain language with itemized computations of adjustments. Additionally, it directs the Secretary of the Treasury, within 180 days of enactment, to establish abatement request procedures (in writing, electronically, by phone, or in person); and, within 18 months of enactment and in consultation with the National Taxpayer Advocate, to implement a pilot program sending a statistically significant portion of such notices by certified or registered mail with e-signature receipt confirmation and report to Congress on error numbers and amounts, abatements, taxpayer responses, and certified mail effectiveness.