## Facts

- Husband and wife married in 1948, separated in 1971, and had four children.
- With independent counsel, the parties executed a comprehensive separation agreement in February 1973 settling property and support matters, including transfers, testamentary provisions, and trusts.
- The agreement stated it would be offered in any divorce proceeding and, if accepted, incorporated by reference into the decree.
- The agreement also provided that, even if incorporated, it would not merge into the decree but would survive as binding on the parties, and that any modification or waiver must be in a signed writing executed with the same formality.
- In the ensuing divorce action, the husband requested incorporation by reference of the agreement.
- The circuit court entered a final divorce decree in June 1973 approving the agreement, incorporating it as if fully set forth, and ordering performance of its obligations.
- In 1981, the husband petitioned in the divorce action to set aside the agreement as void, alleging mental incompetence at the time of execution.
- The wife moved to strike, asserting the petition was an impermissible collateral attack barred by res judicata.

## Issues

1. Whether a separation agreement expressly approved and incorporated, but not merged, into a final divorce decree may later be collaterally attacked on the ground that a party was mentally incompetent when executing the agreement.

## Decision

- The trial court struck the husband’s petition, concluding he failed to show grounds (fraud, mistake, or irregularity) to reopen the final decree.
- The intermediate appellate court affirmed.
- The state’s highest court affirmed, holding that the decree’s approval and incorporation of the agreement conclusively established the agreement’s validity and barred a later collateral attack.

## Legal Principles

- Merger substitutes decree-based rights and duties for those in the agreement; a merged agreement is absorbed into the decree and is generally subject to modification and contempt enforcement.
- Incorporation without merger reflects intent that the agreement remain a separate contract not superseded by the decree, typically enforceable through contract remedies (and, depending on the decree’s terms, potentially through decree enforcement mechanisms).
- When a court expressly approves and incorporates a separation agreement into a final divorce decree, the validity of the agreement is adjudicated and is res judicata in later proceedings.
- A non-merger clause preserves the agreement’s independent contractual status but does not permit collateral attacks on validity once the agreement has been approved and incorporated into a final, unappealed decree.
- A party seeking relief from a final equity judgment must satisfy the limited standards for reopening the judgment (such as fraud, mistake, or irregularity); absent such a showing, collateral challenges are barred.

## Conclusion

A separation agreement that survives as an independent contract because it is incorporated but not merged into a divorce decree still gains claim-preclusive protection once the court approves and incorporates it into a final decree; later attempts to void the agreement—such as on alleged mental incompetence at execution—constitute barred collateral attacks absent grounds to reopen the decree.


Johnston v. Johnston, 297 Md. 48, 465 A.2d 436 (Md. 1983)