From the website:

Beam has a capped total supply, standing at 262,800,000 total coins. Our emission schedule is as follows:

• First year’s block reward is 80 coins per block
• Years 2,3,4 and 5 - 40 coins per block
• In years 6-9 the block reward is 25 coins.
• Afterwards, halving every four years until year 133, when emission stops

In the first five years of Beam existence, additional coins will be emitted to the Treasury:

• First year: 20 coins per block
• Years 2,3,4 and 5 - 10 coins per block

Source: https://www.beam.mw/faq/what-is-beams-emission-schedule