The instructions for IRS Form 1040 for the 2015 tax season can be downloaded from the IRS website. Paper copies of the instruction book can be picked up from an institution that is licensed to distribute tax forms such as a post office, IRS office or library.
The IRS generally makes tax forms, instructions and other products available by the end of January following the tax year. In 2015, the tax filing season began on January 20. 1040 forms and instructions were available at that time for pick-up in person, accessing online and ordering through the mail. The 1040 form comes packaged with an instruction booklet, so tax payers only need one document.