To better understand age-related disparities in US maternal mortality, we analyzed 2016-2017 vital statistics mortality data with cause-of-death literal text (actual words written on the death certificate) added. We created a subset of confirmed maternal deaths which had pregnancy mentions in the cause-of-death literals. Primary cause of death was identified and recoded using cause-of-death literals. Age-related disparities were examined both overall and by primary cause. Compared to women <35, the 2016-2017 US maternal mortality rate was twice as high for women aged 35-39, four times higher for women aged 40-44, and 11 times higher for women aged 45-54 years. Obstetric hemorrhage was the leading cause of death for women aged 35+ with rates...