Motion to Dismiss vs Summary Judgment: When Each Wins

A motion to dismiss attacks the legal sufficiency of the pleadings before discovery; a motion for summary judgment attacks the factual sufficiency of the evidence after discovery. Both can end a case without trial, but they happen at different stages, apply different standards, and rest on different records. Filing the wrong one at the wrong time wastes the motion and can even waive defenses.

This guide compares the two motions side by side, explains when one converts into the other, and walks through the strategic decision of whether to file a 12(b)(6) motion early, skip it and move for summary judgment after discovery, or do both. Read this beside the more general motion to dismiss overview If you want the underlying Rule 12(b) framework first.

Side-by-Side Comparison

Feature	Motion to Dismiss	Summary Judgment
Rule	FRCP 12(b)	FRCP 56
Stage	Pretrial, before answer	After discovery
Deadline	Within 21 days of service	30 days after close of discovery (default)
Record	Complaint only	Full discovery record
Standard	Plausibility (Twombly/Iqbal)	No genuine dispute of material fact
What court accepts	Allegations as true	Evidence in light most favorable to non-movant
Evidence allowed	None outside pleadings	Affidavits, depositions, exhibits
If granted	Case dismissed (often with leave to amend)	Final judgment for movant
Cost to brief	$2,500-$10,000	$15,000-$75,000
Typical grant rate	30-40 percent (full dismissal)	50-70 percent on individual claims

The Conceptual Difference

A motion to dismiss asks: "Even if everything the plaintiff says is true, is there a legal claim here?" A motion for summary judgment asks: "Now that we have evidence, is there a genuine factual dispute that requires a trial?" The first is a legal question decided on the four corners of the complaint; the second is an evidentiary question decided on a developed record.

The Supreme Court articulated the summary judgment standard in Celotex Corp. V. Catrett, 477 U.S. 317 (1986), Anderson v. Liberty Lobby, Inc., 477 U.S. 242 (1986), and Matsushita Electric Industrial Co. V. Zenith Radio Corp., 475 U.S. 574 (1986). Together they hold that summary judgment must be granted "if the movant shows that there is no genuine dispute as to any material fact and the movant is entitled to judgment as a matter of law." A "genuine" dispute exists only if a reasonable jury could return a verdict for the non-moving party.

When a Motion to Dismiss Converts Into Summary Judgment

Under Federal Rule 12(d), if a court considers materials outside the pleadings on a 12(b)(6) motion, the motion must be treated as one for summary judgment under Rule 56, and the court must give all parties "a reasonable opportunity to present all the material that is pertinent to the motion." This conversion happens often when defendants attach contracts, prior court rulings, or correspondence to their motion to dismiss.

There are exceptions. Courts may consider documents attached to or incorporated by reference in the complaint, matters of public record (like court filings or SEC disclosures), and judicially noticeable facts without converting the motion. But once the court considers an affidavit, deposition transcript, or document the plaintiff did not rely on, conversion is automatic and the court must allow discovery if the non-movant requests it under Rule 56(d).

The conversion rule also has a jurisdictional carve-out worth knowing. Rule 12(d) applies only to motions under Rule 12(b)(6) and Rule 12(c). A factual attack on subject-matter jurisdiction under Rule 12(b)(1) works differently: the court may weigh affidavits, documents, and even the results of limited jurisdictional discovery without converting the motion, because no presumption of truthfulness attaches to jurisdictional allegations. A defendant holding evidence that defeats jurisdiction, such as proof of mootness or a plaintiff's lack of standing, can therefore introduce it at the pleading stage without triggering Rule 56 procedures.

Strategic Sequencing

Defendants generally file a motion to dismiss first if any 12(b) ground is plausible, because a successful motion ends the case at the cheapest possible point. If the motion is denied, the defendant answers, takes discovery, and moves for summary judgment after the close of discovery. The two motions are not duplicative; they apply different standards on different records.

A defendant who skips the motion to dismiss is not foreclosed from raising 12(b)(6) defenses later: the defense can be raised in the answer, at trial, or by post-answer motion under Rule 12(c) (motion for judgment on the pleadings), which uses the same standard as 12(b)(6). The 12(b)(6) defense is preserved through trial. But waivable defenses (personal jurisdiction, venue, service) must be raised in the first responsive pleading or motion, or they are gone.

Why Judges Deny Motions to Dismiss But Grant Summary Judgment

Judges hesitate to grant motions to dismiss because the record is thin and the standard requires accepting all allegations as true. The same case can survive a motion to dismiss and lose on summary judgment once the plaintiff is required to put forward actual evidence. A complaint can plausibly allege "defendant breached the contract by failing to deliver" and survive 12(b)(6); when summary judgment requires the plaintiff to produce evidence of breach, and the only emails show timely delivery, the case dies.

This is why summary judgment is a more powerful weapon for defendants in cases that survive motions to dismiss. The plaintiff has spent months or years on discovery, and now must come forward with admissible evidence on every element. Cases that look strong on the pleadings often crumble when the evidence comes in.

What About Plaintiffs?

Plaintiffs almost never file motions to dismiss; the defendant is the only party who answers the complaint. But plaintiffs do file motions for summary judgment, particularly when the defendant's answer admits dispositive facts, when discovery responses produce admissions, or when the defenses raised are legally insufficient. Plaintiffs also file partial summary judgment motions on individual elements (e.g., establishing breach but leaving damages for trial) to simplify the trial.

Summary Judgment vs. Summary Dismissal: Avoid the Confusion

"Summary judgment" and "summary dismissal" are different things. Summary judgment is a federal civil procedure motion under Rule 56. "Summary dismissal" most often refers to employment law (an immediate firing without notice for serious misconduct) and is unrelated to civil procedure. The major difference is that civil dismissal comes through court motion practice, while summary dismissal in the employment context is an immediate termination with no notice and no pay in lieu. Don't confuse the two when reading legal commentary or template forms.

When You Need Help

Both motions are technically demanding. A poorly drafted motion to dismiss waives defenses; a poorly drafted summary judgment motion produces a denied ruling that hardens the case for trial. The attorney-drafted motion to dismiss service Handles the early-stage filing; for cases that have moved past the pleading stage, the summary judgment service Covers the post-discovery motion. Both come with citations to controlling Rule 12 or Rule 56 standards and recent jurisdiction-specific decisions.

Related Civil Procedure Guides

• motion to dismiss strategy
• 12(b)(6) failure-to-state-a-claim motion
• sample motion to dismiss with annotations
• demurrer vs. Motion to dismiss in California
• with vs. Without prejudice differences

Frequently Asked Questions

Can a court convert a motion to dismiss into a motion for summary judgment?

Yes. Under FRCP 12(d), if matters outside the pleadings are presented to the court on a 12(b)(6) motion and not excluded, the motion must be treated as one for summary judgment under Rule 56. The court must give all parties a reasonable opportunity to present material relevant to summary judgment. Practitioners often deliberately attach extrinsic evidence to force conversion when summary judgment is the stronger procedural posture.

Why would a judge deny a motion to dismiss?

A judge denies a motion to dismiss when the complaint plausibly states a claim under Twombly And Iqbal. If there is sufficient factual matter, accepted as true, to state a claim that is plausible on its face, the case proceeds. Judges err on the side of letting cases through the pleading stage rather than cutting off potentially meritorious claims, particularly in fact-intensive cases like discrimination, breach of contract, and tort.

Can a motion to dismiss be converted to a motion for summary judgment?

Yes. Under Federal Rule of Civil Procedure 12(d), including exhibits to a motion to dismiss may convert the motion into a motion for summary judgment. There are exceptions, such as including as an exhibit a document that the plaintiff relied on in its complaint, or matters of public record and judicially noticeable facts. When conversion happens, the court must give the non-moving party a reasonable opportunity to present pertinent materials and may allow additional discovery under Rule 56(d).

What is the difference between dismissal and summary dismissal?

Civil dismissal under Rule 12(b) is a court-ordered end to a lawsuit based on legal defects in the complaint. "Summary dismissal" is an employment law term meaning immediate termination without notice. The two are unrelated: civil dismissal comes from court motion practice, while summary dismissal in employment is an immediate firing with no form of notice and no pay in lieu of notice. The terms are sometimes confused in casual commentary but operate in entirely different legal contexts.

What is the difference between a Rule 12(c) motion and summary judgment?

A motion for judgment on the pleadings under Rule 12(c) is filed after the pleadings close but applies the same plausibility standard as a 12(b)(6) motion: the court accepts well-pleaded allegations as true and looks only at the pleadings and their exhibits. Summary judgment tests the evidence instead; see the movant's summary judgment playbook for that side of the line. Rule 12(c) sits between the two motions in timing but belongs with the motion to dismiss in substance, and if matters outside the pleadings are considered, Rule 12(d) converts it to summary judgment as well.

Does filing a motion to dismiss stop discovery?

Not automatically in most federal courts. Discovery obligations generally continue while a 12(b)(6) motion is pending unless the court grants a protective order staying discovery, although many judges informally defer heavy discovery until the motion is decided. The major statutory exception is the Private Securities Litigation Reform Act, which automatically stays discovery in covered securities cases while a motion to dismiss is pending. Summary judgment presents the opposite posture: by the time it is filed, discovery is usually complete.

What happens if a motion to dismiss is denied?

The case moves forward and the defendant must answer the complaint. Under Rule 12(a)(4)(A), the responsive pleading is due within 14 days after notice of the court's denial. Denial decides only that the complaint states a plausible claim; it resolves no facts, and the same substantive arguments frequently return in a summary judgment motion once discovery reveals what the evidence actually shows.