:)Glory to Jesus Christ!
Paradosis is correct as to the canon as seen in the Rudder---three Sunday Divine Liturgies and one has excommunicated him/herself from the church by choice because they have not communed--- i.e. the have ex- commun-icated themselves. At this point condfession to a priest, counsel and absolution return the sinner to the fold of Communion with the Church. It should be noted that excluded from this "excommunication" would be those who work for the health and salvation of the people (i.e. Doctors, nurses, those carrying for the ill and infirm, police, soldiers, etc) however to these are laid on other requirements such as the reading of the service that one can not attend, to attend to services that are held when they can attend services.
It is interesting to note that in many of the cases of the careproviders for the elderly and ill, it is the responsibility of the priest to visit these people with regularity and provide the sacraments to all who serve God in these callings, thus when the priest visits a hospital, an nursing home, or the home of an invalid he should seek out all Orthodox people and provide them with the opportunity to confess and commune. In a society such as the US, regretfully few priests seek out those workers to provide them the spiritual sustenace they need to be spiritually refueled to care for those they care for.
One of the true tests for a priest who is serving the people as he should is that all the invalid, ill, and elderly who can not attend the Divine Liturgy are communed regularly and provided spiritual support Sadly, many of our elderly and sick are forgotten and abandoned in their last years , especially if they do not have children who advocate for the priest to provide care for this portion of the flock.
One of the great joys in my life in Orthodoxy was when Raphael of Brooklyn was glorified. He has the additional title of seeker for the Lost and Forgotten, may all clergy look to him for the example of their call to find the Fogotten and the Lost.
Your brother in Christ,