After signing and filing a Marital Settlement Agreement (MSA), it becomes the order of the court and to not uphold the terms of that agreement would be a violation of a court order. That being said, if the couple decides to reconcile or remarry after filing an MSA, this does not mean that MSA is void or is no longer the order of the court. The reason is that the MSA from the first marriage summarizes the specific division of that marriage as it applies to the specific parameters of that marriage, i.e.: length of marriage, property incurred during that time, specific agreements between the parties at that time, etc.
Therefore, the MSA reflecting the terms of the first or prior marriage(s) will hold strong, even if there’s a reconciliation or remarriage. But, if there is clear evidence that the parties intended to rescind the MSA upon reconciliation or remarriage, then it may be rescinded.
It is a good idea to address within your MSA the effect reconciliation has on its terms, no matter how unlikely it seems the parties will get back together. For example, the parties can agree that reconciliation will terminate the MSA, or that the parties can only terminate the MSA upon a separate agreement in writing.
There is also the possibility of reconciliation after filing for divorce, but before signing or even drafting an MSA. Any time before a final divorce judgment from the court, the petitioner (or the person who originally filed for divorce) may file a request to dismiss the divorce case. When the court grants this request, it’s as if the divorce never began. This means that the person who filed will have to start all over again from the beginning. This also means that any temporary agreements or orders that were made under the pending divorce case (for example, child custody or support) will be void. The parties will have to start again from scratch should the reconciliation not work out. (Note that this includes having to re-file the petition for divorce and re-pay the $435 filing fee.)
There is the option of requesting a stay of the proceedings, which asks the court to put the case on hold while the parties attempt to reconcile. This is usually a hold of about 90 days. This would allow the parties to pick up where they left off if the reconciliation doesn’t work out.