You don’t need ID to check in with your airline on your phone, and gate agents generally look only at boarding passes, not ID, when you’re getting onto a domestic flight—so your only real hurdle is the airport security checkpoint.
However, it will take extra time with TSA screening. You’ll have to fill out a release form that states your name, the last four digits of your Social Security number, and your home address. “This grants the TSA permission to check your Social Security records.
Once the form is signed, TSA will ask a series of identity-verifying questions. They relay the questions asked by a remote officer who does the actual record checks: Where were you born? What state was your [Social Security number] issued in? What are its last four digits? Mother’s maiden name? Father’s name and place of birth? These questions vary, but they should generally be available on your birth certificate, assuming you’re a natural-born citizen.
Once your identity has been verified to the TSA agent’s satisfaction, you’ll be able to go through the checkpoint. Also, expect additional screening if you’re flying without ID. The passenger will receive a patdown, go through the AIT [advanced imaging technology, or full-body scanner], and have their carry-on bags inspected.”