Q: Does any part of The Urantia Book touch upon the subject of multiple human incarnations (on earth, anyway) for an individual soul?
A: The Urantia Book does teach of multiple instances of human beings being "re-keyed" during our eternal career—we are transformed 570 times in the process of going from a material, mortal being to a spirit being—but not in the sense of being reincarnated, and never on this planet:
48:1.5 The Morontia Power Supervisors are able to effect a union of material and of spiritual energies, thereby organizing a morontia form of materialization which is receptive to the superimposition of a controlling spirit. When you traverse the morontia life of Nebadon, these same patient and skillful Morontia Power Supervisors will successively provide you with 570 morontia bodies, each one a phase of your progressive transformation. From the time of leaving the material worlds until you are constituted a first-stage spirit on Salvington, you will undergo just 570 separate and ascending morontia changes. Eight of these occur in the system, seventy-one in the constellation, and 491 during the sojourn on the spheres of Salvington.
In the days of the mortal flesh the divine spirit indwells you, almost as a thing apart—in reality an invasion of man by the bestowed spirit of the Universal Father. But in the morontia life the spirit will become a real part of your personality, and as you successively pass through the 570 progressive transformations, you ascend from the material to the spiritual estate of creature life. Paul learned of the existence of the morontia worlds and of the reality of morontia materials, for he wrote, “They have in heaven a better and more enduring substance.” And these morontia materials are real, literal, even as in “the city which has foundations, whose builder and maker is God.” And each of these marvelous spheres is “a better country, that is, a heavenly one.”
In contrast, Urantia Book teachings do not include reincarnation on this planet. We do not come back here after our death—as spirits, or as reincarnated personalities, having to live another earthly life. Following are passages showing some history of the concept of reincarnation, and what Jesus taught about it.
94:2.3 The undue concentration on self led certainly to a fear of the nonevolutionary perpetuation of self in an endless round of successive incarnations as man, beast, or weeds. And of all the contaminating beliefs which could have become fastened upon what may have been an emerging monotheism, none was so stultifying as this belief in transmigration—the doctrine of the reincarnation of souls—which came from the Dravidian Deccan. This belief in the weary and monotonous round of repeated transmigrations robbed struggling mortals of their long-cherished hope of finding that deliverance and spiritual advancement in death which had been a part of the earlier Vedic faith.
146:7.2 Jesus further explained to his apostles that the spirits of departed human beings do not come back to the world of their origin to communicate with their living fellows. Only after the passing of a dispensational age would it be possible for the advancing spirit of mortal man to return to earth and then only in exceptional cases and as a part of the spiritual administration of the planet. 164:3.4 There was, throughout all these regions, a lingering belief in reincarnation. The older Jewish teachers, together with Plato, Philo, and many of the Essenes, tolerated the theory that men may reap in one incarnation what they have sown in a previous existence; thus in one life they were believed to be expiating the sins committed in preceding lives. The Master found it difficult to make men believe that their souls had not had previous existences.
The teachings of The Urantia Book forever liberate us from the notion that we have to come back to this little blue planet time after time until we "get it right." Instead, we are given a thrilling revelation of the eternally ascending life and the endless adventure of finding God as a progressive experience, and as spirit beings. We do indeed get it right during our afterlife, but in increasingly spiritual surroundings. Our residual human "baggage" is corrected and cured early in our eternal career as a part of the Father's merciful deficiency ministry, and we move forward by our own abilities, choices and desires.