The rules package passed by a near full party line vote of 220-213 on Monday. Not a single Democrat voted in favor of the package.
McCarthy brokered a deal with fellow House Republicans to change several chamber rules, including allowing a single member to call for the speaker’s removal at any time and limiting government spending.
The new House speaker in a tweet said the new rules will empower members to debate and increase transparency as opposed to the previous Democratic-run House that silenced voices and "allowed for unconstitutional proxy voting."
"Congress has been broken for a long time. Over the years, a concentration of power within the Speaker’s Office has kept lawmakers on the legislative sidelines. Lawmaking should be open to all members - not just a select few - so that the best ideas win," McCarthy said.
The House then began debate on the first piece of legislation in the Republican-majority Congress, which calls for repealing $80 billion in funding for the US federal tax agency - the Internal Revenue Service (IRS).
McCarthy received 216 votes to win the House speakership shortly after midnight on Saturday after 15 rounds of votes.
The House met last Tuesday in its first session of the 118th Congress, during which the majority party typically elects a speaker. However, opposition by a number of Republicans, mostly from the ultraconservative Freedom Caucus, over the course of over a dozen ballots blocked McCarthy's leadership bid for nearly four days.
The situation marked the first time in a century that the House failed to elect a speaker on the first ballot, and the first time since 1859 the chamber took more than 10 ballots to come to a conclusion.
On Monday, Congressman Jim McGovern said he was concerned by the "back-room deals that Speaker McCarthy made with the Freedom Caucus in exchange for their votes."
Democratic Congressman Steny Hoyer during comments on the House floor said he opposed the Republicans' "extreme rules package," which targets hard-working federal employees, obstructs investigations, and makes it easier for the ultra-wealthy to cheat on their taxes.