Under current law, taxpayers who lose an argument with the IRS can generally avoid penalties by showing they tried in good faith to comply with the tax law. In a broad range of circumstances, the health-care bill would change the law to impose strict liability penalties for income-tax underpayments, meaning that taxpayers will no longer have the luxury of making an honest mistake. The ability of even the IRS to waive penalties in sympathetic cases would be sharply curtailed.
via James M. Peaslee: Tax Penalties and the Health-Care Bill – WSJ.com.