These are the instructions for 1128 Application To Adopt Change or Retain a Tax Year. File Form 1128 to request a change in tax year. Partnerships, S corporations, or personal service corporations (PSCs) may be required to file the form to adopt or retain a certain tax year. Availability: Usually ships the next business day. 1128 Instructions For Application To Adopt Change or Retain a Tax Year 1128INS$5.95