The long-term anneal behavior of the integrated dose records -threshold voltage of PMOS dosimeters at room temperature has been studied. The results showed that tunneling anneal of trapped holes in oxide and the buildup of interface states post-irradiation are two important mechanisms of the annealing. The bias conditions during irradiation and annealing affect the direction and magnitude of threshold shifts caused by room temperature annealing. The irradiation records can be maintained well at negative bias voltage.