via USCCB:

Pope Francis has accepted the resignation of Cardinal Theodore McCarrick, Archbishop Emeritus of Washington, from the College of Cardinals.

Pope Francis has also imposed on Cardinal McCarrick suspension ad divinis and directs him to observe a life of prayer and penance in seclusion until the completion of the canonical process.

via Crux:

The pope’s decision comes over a month after the Archdiocese of New York announced that allegations of sexual abuse against McCarrick had been deemed “credible and substantiated,” following an investigation by an archdiocesan review board.

The victim was a 16-year-old altar boy who accused McCarrick of abusing him at St. Patrick’s Cathedral in 1971 and 1972, while he was still a priest for the archdiocese of New York.

Following those revelations, Vatican Secretary of State Cardinal Pietro Parolin ordered McCarrick to no longer exercise public ministry.