What are the series codes for different types of patent applications?

The USPTO assigns different series codes to various types of patent applications:

• 01/ – 16/: Nonprovisional applications (utility, plant, and reissue)
• 29/: Design applications
• 35/: International design applications
• 60/, 61/, and 62/: Provisional applications
• 90/: Ex parte reexamination proceedings
• 95/: Inter partes reexamination proceedings
• 96/: Supplemental examination proceedings and resulting ex parte reexamination proceedings

The MPEP provides a detailed breakdown of series codes for nonprovisional applications from 1925 to the present. For example, ‘Series code 16 is assigned to nonprovisional applications filed from June 2018 to present.’ (MPEP 503)