Credit Union Governance Modernization Act of 2021 This bill revises the procedure for expelling members from a federal credit union. Specifically, a member may be expelled for cause pursuant to a policy adopted by a majority vote of a quorum of the directors of a credit union. Currently, a member may be expelled by a two-thirds vote of the credit union membership present at a special meeting. The member may request a hearing from the board of directors. After the hearing, the board shall hold a vote on expelling the member. The expelled member may request reinstatement through a two-thirds vote of the members present at a meeting. Member conduct that may be cause for expulsion includes a material loss to the credit union, a violation of the credit union membership agreement, a substantial disruption to the operations of a credit union, fraud or attempted fraud, and other illegal or inappropriate behavior.