Also known as a parent-subsidiary merger, a short-form merger is a merger between a parent company and its substantially (but not necessarily wholly) owned subsidiary, with either the parent company or the subsidiary surviving the merger. A short-form merger does not require approval of the stockholders of the subsidiary. The requirements of a short-form merger are dictated by state statute.

If a buyer acquires less than 100% (but generally at least 90%) of a target company's outstanding stock, it may be able to use a short-form merger to acquire the remaining minority interests. The merger allows the buyer to acquire those interests without a stockholder vote, thereby purchasing all of the target company's stock. This merger process occurs after the stock sale closes, and is not a negotiated transaction.

An intermediate-form merger is a different type of merger. An intermediate-form merger is a special type of merger permitted by Section 251(h) of the Delaware General Corporation Law (DGCL) (DGCL § 251(h)) for Delaware public corporations that allows a bidder in a tender offer to complete the back-end merger without stockholder approval at a lower ownership threshold than a short-form merger (typically just a majority of the target company's outstanding shares) if the statutory conditions set out in DGCL §251(h) are met.

For more information on the use of short-form mergers, see: