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
IRS - When to Call Us
Call us about your refund status only if Where's My Refund directs you to contact us.
IRS phone numbers and tax help options
