A US citizen or resident files this form to request an automatic extension of time to file a US individual income tax return. A tax extension is a request for an additional six months to file a tax return with the IRS.An extension request is only for filing the tax return. An extension extends the time to file your tax return, it does not allow an extension of time to pay any taxes owed. Filing IRS Form 4868 gives you an automatic sixmonth extension to file your tax return. Disaster-related casualty losses. The court must find "extraordinary circumstances" to grant an extension. Use IRS Form 4868 to apply for a filing extension if you need additional time to complete your federal income tax return. A tax return extension gives you six more months to file, but you must still pay your taxes on time. You may request a STEM I-20 and apply for STEM OPT with USCIS up to 90 days before the expiration of your Post-Completion OPT EAD.