Typically, accepting the settlement offer will bar one from pursing legal action against the same entity for the same issue. One can deny a settlement offer to allow for future lawsuits. Rejecting an offer does not automatically close one's case, rather it keeps one's legal options open (e.g. different settlement, negotiations, litigation). Accepting a settlement and cashing the check typically involves signing a release that gives up the right to bring future claims related to the incident.