This National Toxicology Program technical report describes 900 MHz whole-body RFR exposures (GSM and CDMA) in male and female Sprague Dawley rats from in utero through up to 2 years. The report concludes clear evidence of carcinogenic activity in males for both modulations based on malignant schwannoma of the heart, with malignant glioma of the brain also reported as related to exposure. In females, the report concludes equivocal evidence of carcinogenic activity for both modulations based on selected tumor outcomes, and genetic toxicology findings were mixed with some comet assay increases/equivocal results but negative micronucleus assays.