Researchers are looking for other ways to treat pulmonary arterial hypertension (PAH). Sotatercept is a study medicine that is designed to treat PAH. A past study, MK-7962-024 (LIGHTRAY) (NCT06664801), learned about the safety and effects of sotatercept in people with PAH. One of the goals of that study was to learn about sotatercept when given at a dose (amount) based on the weight range a person is in (weight-banded doses) compared to when given based on a person's exact weight. This is an extension study, which means people who took part in MK-7962-024 (LIGHTRAY) may be able to join this study. In this extension study, people will get weight-banded doses of sotatercept. The main goal of this study is to learn about the safety of weight-banded doses of sotatercept and if people tolerate it over a longer period of time.