Am I not supposed to receive the Holy Eucharist If I have reached late for Holy Mass?

This is a question I am sure that many have pondered over after arriving late for the Holy Mass. Before diving into what the Church teaches regarding this, let me clarify one thing at the beginning itself. This question is completely different from the one which goes something like this – How late can I come for mass and still fulfil  my obligation on Sunday and other holy days? For this the answer is simple – If there is no genuine reason behind coming late for the mass, then one will have to attend a different one to fulfil the obligation (the key word being ‘genuine’). 

Let us now get back to the original question – How late can I come and still receive communion? The Code of Canon Law mentions the following regarding receiving sacraments:

1. Can. 843 §1 Sacred ministers cannot deny the sacraments to those who seek them at appropriate times, are properly disposed, and are not prohibited by law from receiving them. 
2. Can. 912 Any baptized person not prohibited by law can and must be admitted to holy communion. 

As you can see, there is no mention whatsoever regarding any time limit within which one has to come to become eligible to receive communion. The only requirements put forth here are:

1. Communion has to be sought at appropriate times – Receiving communion during mass while it is being offered to the faithful clearly is an appropriate time. Just do not go knocking on the Priest’s door at three in the morning unless it is a dire situation.
2. One has to be properly disposed – This would include not being in a state of mortal sin, keeping the Eucharistic fast etc. For better understanding I would recommend reading CCC 1384 – 1390. Here too you will find that there is no mention regarding attending a specific time period in the holy mass before receiving communion.
3. There is no prohibition by law – Can. 915 and 916 talk about who all should not be admitted to holy communion. These include those who are interdicted (excluded from participation in certain holy things) and those who are  conscious of grave sin. Again there is no mention of prohibition for those arriving late for mass.

In short, one could be walking in while the communion is being offered and still walk up to the priest and receive the communion. Did you fulfil the Sunday obligation? The answer would be – “Absolutely not”. The mass is a single act of worship which begins with the entrance procession and ends with the final blessing and we should be there from beginning to end.