2026 MLB Topps Series I Mega Box

Topps' flagship series is split across the season, with Series I making up the first part of the checklist, followed by Series II and Update later in the year. This is where the year's base design is introduced, the one that then returns in the later releases, and the rookie cards are recognised by the RC logo. For many collectors, Series I is therefore the starting point when work on the year's base set begins.

Topps Series I is the flagship release that opens every baseball season and lays the foundation for the year's base set, with team cards, stars and rookie cards for players who have recently debuted in MLB. The mega box is a separate retail format with parallel cards printed only for this particular version, alongside the regular base design. The box is sealed from the manufacturer and the cards are in English.

A sealed mega box. It holds more packs than the value format and contains exclusive parallel cards found only here.