At the monastery Theodosius passed through the various obediences: he carried water, chopped fire-wood, milled flour and baked bread. He went to Totma on the igumen’s orders to search for a salt-works for the monastery. He sought the permission of Tsar Ivan Vasilevich and the blessing of Archbishop Nicander to found a monastery at Totma. Theodosius was appointed head of this newly-formed Totma monastery, which in a grant of 1554 was declared free of taxation.
The saint founded the Totma Ephraimov wilderness monastery and brought brethren into it. Eventually becoming the head of two monasteries, Theodosius continued to lead an ascetic life. He wore down his body by wearing chains and a hairshirt, and beneath his monastic cowl he wore an iron cap. Fond of spiritual reading, he acquired many books for the monastery. Saint Theodosius reposed in the year 1568 and was buried in the monastery he founded, and miracles occurred at his grave.
On September 2, 1796 during the reconstruction of the Ascension church, his relics were found incorrupt, and their glorification took place on January 28, 1798, on the day of his repose.