Certain TAS telephone numbers are being used in a spoofing scam. Taxpayers are targeted by either robocalls or live solicitors claiming to be with TAS or the IRS. The caller ID displays a TAS number, but it is a scam.
If you receive such a call, report it immediately to https://www.treasury.gov/tigta/contact_report_scam.shtml.
For more information, see the Report Phishing and Online Scams page on IRS.gov: https://www.irs.gov/privacy-disclosure/report-phishing.