Sens. John Kennedy (R-La.) and Mazie Hirono (D-Hawaii) have introduced bipartisan legislation that would allow service members to sue the government for military medical malpractice. Because of the Feres Doctrine, a ruling from 1950, service members cannot bring lawsuits against the government for negligence or wrong doing.
Source: https://taskandpurpose.com/feres-doctrine-senate-bill