Background Childhood maltreatment (CM) significantly increases the risk of developing post-traumatic stress disorder (PTSD) for which the prevalence in Europe is higher than initially assumed. While the high economic burden of PTSD is well-documented, little is known about the health care cost differences between individuals with PTSD-CM and those without PTSD in Germany. This study aimed to determine the excess health care and absenteeism costs associated with PTSD-CM in Germany. Methods Baseline data from a multi-center randomized controlled trial on individuals with PTSD-CM (n = 361) were combined with data from individuals without PTSD (n = 4760). Entropy balancing was used to balance the data sets with regard to sociodemographic characteristics. Six-month excess health care costs from a societal perspective were calculated for 2022, using two-part models with logit specification for the first part and a generalized linear model for the second part. Results The total six-month excess costs associated with PTSD-CM were €8864 (95% CI: €6855 to €10,873) per person. Of this, the excess health care costs accounted for €4647 (95% CI €3296 to €5997) and the excess costs of absenteeism for €4217 (95% CI: €3121 to €5314). Individuals with mild to moderate PTSD symptoms incurred total excess costs of €6038 (95% CI: €3879 to €8197), while those with severe to extreme symptoms faced €11,433 (95% CI: €8220 to €14,646). Conclusions Excess health care and absenteeism costs associated with PTSD-CM were substantial, with absenteeism accounting for roughly half of the total excess costs.