It's important to note that, once the IRS assigns an IP-pin (identity protection pin), you must use it when e-filing every year after, and the IP pin changes every year. The IRS should mail it to your address of record in December, or you can retrieve it online.
https://www.irs.gov/identity-theft-fraud-scams/retrieve-your-ip-pin
Without the IP pin, you can't e-file. Even if you mail your return, processing will be delayed unless you write your IP pin in the spot next to your signature.
Also note, the IP pin is 6 digits. You still need a 5 digit e-filing PIN or your AGI in addition to the 6 digit IP pin.
