ACH says: US TREASURY 220 TAX REFUND PPD ID?
If it says: "US TREASURY 220 TAX REFUND PPD ID" or something very, very similar, then your refund came directly from the IRS and did not detour through a preparer's bank account. This means you would be eligible for a direct deposit of your rebate check.
If it says "SBBT" or "Refunds Now" or anything else, you will only get the rebate as a paper check.
Hats off to Judy for pointing this out!