Prosecutors said they want an extra 20 years added on, fearing 31-year-old Matthew Louis Reese could get out in 27 years for probation.
“The defendant is a threat to the Dallas County community and the state believes if he gets out, he will do this again,” said prosecutor Soni Lewis.
Reese was sentenced Wednesday after pleading guilty earlier to charges that include sexual assault and aggravated sexual assault.
Reese could face additional prison time Thursday when a judge considers his punishment on another count of assault.
Investigators said Reese had a sexual relationship with the girl and passed the virus to her.
The now 17-year-old girl testified she would not have been with Reese if he told her about his HIV status.
At least two others testified during Reese's trial that he never told them prior to having sex that he carried the virus that causes AIDS.
“Being HIV positive and having sex with a person and not telling them, that is worth 55 years," said defense attorney Allan Fishburn. "Mr. Reese acknowledges that. That is why we are here and having this hearing. It would be an abuse of discretion if this court makes these sentences run consecutively in this case.
NBC 5's Holley Ford contributed to this report.