When May the Tabernacle Be Left Open?

In short, the tabernacle may be left temporarily opened during Mass at Communion time, when ministers are nearby to prevent any profanation of the Blessed Sacrament that remains therein, and additional consecrated Hosts may be easily accessed if needed.

In addition, the tabernacle may be left temporarily open when the Blessed Sacrament is not inside. A classic example is after Holy Thursday Mass, when a Eucharistic procession takes place and the Blessed Sacrament is reposed elsewhere. Then, at the Easter Vigil Mass, the Eucharist is consecrated anew and the remaining consecrated Hosts placed in the tabernacle afterward.