To claim a refund, you must file an amended return within 3 years after the date you filed your original return or 2 years after the date you paid the tax. Many find the easiest way to figure the entries for Form.X is to first make the changes in the margin of the return they are amending. Receive an IRS 4364C letter? Fill out the correct form for your business. 1. Review your return for additional errors or omissions. 2. Your Form 1095B is proof of healthcare insurance for the IRS and does not require completion or submission to DHCS. Please keep this form for your records. Once the IRS finishes processing the original return, if they don't catch your error, then you can file an amended return. Form Number, Form Name, Category.