If you are referring to your 5-digit pin to e-file, the IRS has discontinued the e-filing PIN option. To verify your identity for e-filing, you’ll need to use last years AGI. If you are referring to your 6-digit IP (Identity Protection) Pin, you can retrieve that online at the IRS's Get an IP PIN site, or call the IRS at 1-800-908-4490 to have an IP PIN mailed to you.
What happened to the e-filing PIN? - Community