Mega Millions went up to $5 on April 8, 2025 , when the game relaunched with a new ticket price and prize structure. The change applied to the new version of the game after the final drawing of the old format on April 4, 2025.
The price increase came with several other changes. Jackpots started at $50 million instead of $20 million, non-jackpot prizes were raised, and the game added a built-in multiplier that could boost secondary prizes.
Before that change, Mega Millions tickets had cost $2. The overhaul was announced in March 2025, and the first drawing under the new rules took place on April 8, 2025.
If you were asking about when the ticket price became $5, the short answer is April 8, 2025. If you meant something else, such as when the jackpot itself first reached $5 million or $5 billion, that would be a different date.