Republican Congressman Mark Green has announced his resignation from Congress after the upcoming budget vote, which will reduce the GOP margin by one vote.
Republican Congressman Mark Green has resigned, eroding the GOP margin by one vote.

FactVerify
Source: factverify.com
What the Evidence Shows
The claim states that Republican Congressman Mark Green has resigned, eroding the GOP margin by one vote. Multiple reliable sources confirm that Mark Green, a Republican representative from Tennessee, has announced his intention to resign from Congress after the House votes on a major budget reconciliation bill related to President Donald Trump's agenda. This resignation is planned to take effect shortly after the vote, meaning he remains in office until then but will leave his seat vacant afterward.
Since he is a Republican member of the House, his departure will reduce the number of GOP seats by one, thereby eroding the Republican margin in the House by one vote. The sources do not indicate any immediate resignation before the vote, but the planned resignation is confirmed and will impact the GOP's numbers once effective.
Therefore, the claim is accurate in its core assertion that Mark Green's resignation will reduce the GOP margin by one vote.