Johnston v. Johnston 297 Md. 48, 465 A.2d 436 (1983) Mr. Johnston and Mrs. Johnston were married for over 20 years and had 4 children. But things turned sour and they decided to separate. The Johnstons each got a lawyer, and sat down and negotiated a separation agreement. The separation agreement was a contract that divided property, provided Mrs. Johnston with spousal support, etc. The Johnstons then filed for divorce and requested that the separation agreement be incorporated by reference into the divorce decree. The separation agreement explicitly said that it was to be incorporated, but not merged, with the divorce decree. Basically, that means that the separation agreement was not formally part of the divorce decree, but it was its own separate contract. The separation agreement explicitly said that it could not be modified, even if there was a material change in circumstances. The Court approved the divorce, incorporated the separation agreement, and everybody walked away happy. Eight years later, Mr. Johnston came back to Court and asked for the separation agreement to be declared void. Mr. Johnston argued that he had recently discovered that he was suffering from a mental defect during the separation, and so was not competent to sign a contract. The Trial Court found for Mrs. Johnston. Mr. Johnston appealed. The Trial Court found that under Maryland law (Md. Rule 625a), after 30 days, you could only challenge a divorce decree if there was fraud, mistake or irregularity. Therefore, it was too late for Mr. Johnston to challenge the decree. Mr. Johnston argued none of these things. The Appellate Court affirmed. Mr. Johnston appealed. The Maryland Supreme Court affirmed. The Maryland Supreme Court found that due to the non-merger clause, the separation agreement was separate from the divorce decree and so was not subject to the limitations of 625a. However, the Court found that once the separation agreement was approved by the court and incorporated into a divorce decree, the validity of the separation agreement is established, and Mr. Johnston is prevented from attacking it due to res judicata. Although courts can always modify a divorce degree as they see fit, they cannot not modify a separation agreement that isn't merged, so Mr. Johnston was out of luck. The separation agreement is a separate, enforceable private contract, and the courts cannot modify private contracts. There are several advantages to having a separation agreement incorporated but not merged: The court cannot modify the agreement sua sponte. The agreement can be enforced through the contempt power of the court. The agreement is entitled to res judicata.