When are Schedules M$-1$ and M$-3$ for Form $1120-$S required?

A shareholder in the corporation is an entity that owns directly or indirectly $50\%$ or more of the shares. In that case, Schedule M$-3$ is required, but Schedule M$-1$ is not always required. However, S corporations may voluntarily submit Schedule M$-1.$

For Schedule M$-1,$ the S corporation's total receipts exceed $$250,000$; for Schedule M$-3,$ there is no total receipts threshold. Or$,$ when total assets at year's end exceed $$250,000$ for Schedule M$-1,$ or total assets at the end of the year exceed $$10$M for Schedule M$-3.$

Schedule M$-1$ is required when there are fewer than $100$ shareholders, and Schedule M$-3$ is required when there are more than $100$ shareholders.

For Schedule M$-1,$ the S corporation's total receipts exceed $$500,000$; for Schedule M$-3,$ there is no total receipts threshold. Or$,$ when total assets at year's end exceed $$1$M for Schedule M$-1,$ or total assets at the end of the year exceed $$10$M for Schedule M$-3.$