The Internal Revenue Service (IRS) has issued a critical reminder that April 15, 2026, is the final deadline for filing tax returns or requesting an extension. With an estimated 10 million Americans still unfiled, the IRS warns that failing to meet this deadline can result in penalties starting at 0.5% per month on unpaid taxes, in addition to compounding interest. Even a minor delay can quickly escalate costs. Taxpayers are encouraged to act immediately, either by submitting their returns or requesting an extension, which can be done easily through digital platforms or by mail. However, it's important to note that while an extension allows more time to file, it does not extend the payment deadline. Taxes owed are still due by April 15, and any unpaid amounts will incur penalties and interest. The IRS has also tightened enforcement, making it riskier than ever to ignore the deadline. Taxpayers are advised to pay as much as they can upfront to minimize penalties. For those unable to pay in full, the IRS offers payment plans to help manage tax liabilities effectively.