In June 1988 Archbishop Marcel Lefebvre announced his intention to consecrate de Galarreta and three other priests as bishops. Lefebvre did not have a pontifical mandate for these consecrations, normally required by Canon 1382 of the Code of Canon Law. On June 17, 1988 CardinalBernardin Gantin, prefect of the Congregation for Bishops sent the four priests a formal canonical warning that he would automatically incur the penalty of excommunication if they were to be consecrated by Lefebvre without papal permission. On June 30, 1988 de Galarreta and the three other priests were consecrated bishop by Archbishop Lefebvre and Bishop Antônio de Castro Mayer. On July 1, 1988 Cardinal Gantin issued a declaration stating that Lefebvre, de Castro Mayer, de Galarreta, and the three other newly-ordained bishops "have incurred ipso facto the excommunication latae sententiae reserved to the Apostolic See". On July 2, 1988, Pope John Paul II issued the motu proprioEcclesia Dei, in which he reaffirmed the excommunication, and described the consecration as an act of "disobedience to the Roman pontiff in a very grave matter and of supreme importance for the unity of the Church", and that "such disobedience — which implies in practice the rejection of the Roman primacy — constitutes a schismatic act". Cardinal Darío Castrillón Hoyos, head of the commission responsible for implementing Ecclesia Dei, has said this resulted in a "situation of separation, even if it was not a formal schism." The SSPX denied the validity of the excommunications, saying that the consecrations were necessary due to a moral and theological crisis in the Catholic Church.
SSPX Bishop
Following his episcopal consecration Galarreta was appointed rector of the seminary of La Reja. In 1991, he assisted in the consecration of Licínio Rangel as bishop for the Priestly society of saint John Mary Vianneyafter the death of its founder, bishop Antônio de Castro Mayer. In 1994 he became superior of the Society of Saint Pius X district of Spain and Portugal. In 2002 he became second assistant of the Society. By a decree of 21 January 2009, which was issued in response to a renewed request that Bishop Fellay made on behalf of all four bishops whom Lefebvre had consecrated on 30 June 1988, the prefect of the Congregation for bishops, by the power expressly granted to him by pope Benedict XVI, remitted the automatic excommunication that they had thereby incurred, and expressed the wish that this would be followed speedily by full communion of the whole of the Society of saint Pius X with the Church, thus bearing witness, by the proof of visible unity, to true loyalty and true recognition of the pope's magisterium and authority. The canonical situation of the four bishops thus supposedly became the same as that of the other clergy of the Society, who are suspended a divinis. It was reported that bishop de Galarreta had been named chairman of the SSPX commission in charge of the theological discussions with the Holy See.