To our best understanding of the Scriptures, Moses is neither in heaven, nor on earth any longer.  Speaking of himself, Jesus said:  “And no one has ascended into heaven, but he who descended from heaven, even the Son of Man,” (John 3:13).  Clearly then Moses is not in heaven. 

When Adam lost the right to life in paradise because of disobedience, God told him, and by extension, all of mankind, that he would return to the dust upon dying:  “By the sweat of your face you shall eat bread, till you return to the ground, because from it you were taken: for you are dust, and to dust you shall return,” (Genesis 3:19).  Ecclesiastes further supports this eventuality for all living beings:  “For the fate of the sons of men and the fate of beasts is the same.  As one dies so dies the other; indeed, they all have the same breath and there is no advantage for man over beast, for all is vanity.  All go to the same place.  All came from the dust and all return to the dust,” (Ecclesiastes 3:19, 20).

When he was nearing death, Moses was permitted to see the promised land from the top of Mount Nebo.  But because he had failed to follow God’s directions faithfully, he was not allowed to go there.  When Moses died, the Lord buried him [likely by means of His angels] in the valley of the land of Moab, opposite Bethpeor; but no man knows his burial place to this day,” (Deuteronomy 34:6).  Doubtless Moses’ body has by now deteriorated into dust. 

Yet he sleeps in God’s memory, as do all who die. We await the resurrection back to life in God’s kingdom, for which our Lord Jesus taught us to pray:  “Thy kingdom come, Thy will be done on earth as it is in heaven,” (Matthew 6: 10).  And just as Jesus resurrected Lazarus, who had already begun to decompose in the tomb having been buried three days, similarly will the reigning Christ resurrect Moses and all of mankind.  This we are promised in John 5:28, 29: “Do not marvel at this; for an hour is coming, in which all who are in the tombs shall hear his voice, and shall come forth; those who did the good deeds to a resurrection of life, those who committed the evil deeds to a resurrection of judgment”.

Some may argue that the scripture in Jude 1:9 indicates Moses must be in heaven!  But consider the following:  Michael the Archangel and the devil, who are contending about the "body of Moses", are clearly spirit beings in the spirit realm not the physical one. In  I Corinthians 15:50 we are told that "flesh and blood cannot inherit the kingdom of God", the spirit dimension.  Therefore, the physical body of Moses, his flesh and blood have no place in that realm. Furthermore, the book of Jude was written centuries after Moses passed away, and his body had long ago disintegrated into dust. One can only conclude then that "the body of Moses"  spoken of in Jude is symbolic language, indeed pertaining to something other than the actual, physical body of Moses, and to a subject which requires another discussion altogether.