After the tax return has been Accepted by the IRS (meaning only that they received the return) it will be in the Processing mode until the tax refund has been Approved and then an Issue Date will be available on the IRS website.
See this IRS website for federal tax refund FAQ's - https://www.irs.gov/refunds/tax-season-refund-frequently-asked-questions
Use this TurboTax website to check the status of an e-filed return and if it was either accepted or rejected - https://turbotax.intuit.com/tax-tools/efile-status-lookup/
If accepted by the IRS use the federal tax refund website to check the refund status - https://www.irs.gov/refunds
