A missed base becomes an out only after a timely appeal.

The rule and version used here

This page applies the Office of the Commissioner of Baseball’s 2026 Official Baseball Rules (OBR), the professional code governing MLB and MLB’s professional development league system. The main provisions are Rules 5.06(b)(1), 5.08 and 5.09(b)–(d), plus the definitions of “Appeal,” “Catch” and “Retouch.”

The 2026 edition amended Rule 5.06(b)(1) and added Appendix 6 to clarify a runner’s retouch responsibility. A runner has passed a base when both feet are on the ground beyond the relevant edge in the direction of travel. NCAA, school, youth and international competitions may appoint another code; their procedures must not be assumed from this MLB baseline.

Which baserunning errors are appeal plays?

OBR 5.09(c), read with 5.09(b)(5), (11) and (12), covers four recurring situations:

1. Early departure after a catch: a runner fails to retouch the original base after a fair or foul fly ball is caught. A runner may leave when the first fielder touches the ball, not only when the catch is finally completed.
2. A missed base: while advancing or returning, a runner fails to touch every base in the required order.
3. Failure to return to first: after overrunning or oversliding first base, the runner does not return immediately.
4. Missed home with no return attempt: the runner misses home and makes no attempt to come back.

Awarded bases do not excuse the touching requirement. Rule 5.06(b)(4)(I) specifically allows an appeal after a runner misses an intervening base even though an overthrow awarded the next base.

Passing a runner is not an appeal play

Under OBR 5.09(b)(9), a trailing runner who passes a preceding runner before that runner is out is out when the passing occurs. The defence does not have to preserve and make a missed-base appeal. Abandoning the bases can also produce an umpire-called out under 5.09(b)(2).

Batting out of turn is a separate appeal process under Rule 6.03(b), and an appeal play is not the same as asking for replay review. Keeping those procedures separate matters because they have different triggers and consequences.

Touch in order; return in reverse order

Rule 5.06(b)(1) requires first, second, third and home to be touched in order while advancing. A runner who must go back retraces the passed bases in reverse order. Under the 2026 wording, a returning runner who has passed a base must retouch it before advancing again.

For a caught fly ball, the runner must retouch the original base before advancing. “Tagging up” does not require waiting until the fielder proves the catch: the OBR definition of “Catch” permits the runner to leave the instant the first fielder touches the ball.

The ball must be live and the intent unmistakable

The OBR definition makes an appeal the act of a fielder claiming an offensive rules violation. Rule 5.09(c) requires the ball to be in play. If “Time” has been called, the pitcher first takes the pitcher’s plate with the ball and the plate umpire calls “Play”; only then can the defence complete the appeal.

1. A fielder secures the live ball.
2. The fielder tags the runner or the base that was missed or left too soon.
3. The fielder’s words or conduct clearly identify the intended appeal to the umpire.

Accidentally stepping on a base while holding the ball is not enough. Rule 5.09(c) says a verbal request or another unmistakable act should show the intent. Time is not out during the appeal, so other runners remain live and may advance at their own risk.

A returning runner must be tagged

There are two different missed-home situations. If the runner misses the plate and heads away without trying to return, the catcher or another fielder may hold the ball, touch home and appeal under Rules 5.09(b)(12) and 5.09(c)(4).

If the runner immediately tries to come back, touching home is not enough. The Rule 5.09(b)(12) Comment says the ordinary live play continues and the defence must tag the runner before the runner touches the plate. This distinction prevents a base-only appeal from replacing an active tag play.

When can the runner repair the mistake?

While the ball remains live, a runner can generally retrace the route and touch the missed base before a valid appeal, provided the runner follows the bases in reverse order. Two express limits in Rule 5.09(c)(2) are decisive:

• No runner may return to a missed base after a following runner has scored.
• While the ball is dead, a runner may not return to a missed or prematurely left base after touching a base beyond it.

That dead-ball limit is why a batter-runner who misses first on a home run or ground-rule double may correct the miss before touching second, but not after touching second. An award still requires the runner to touch every intervening base.

The next pitch or play closes the window

Under Rule 5.09(c), the defence must appeal before the next pitch or any play or attempted play. The appeal itself does not count as a play for this deadline, but a balk committed while making the appeal does. A failed first appeal in which the defence throws the ball out of play also prevents a second appeal of the same runner at the same base.

If the violation occurred on a play ending the half-inning, the appeal must come before the defence leaves the field. For this purpose, MLB says the team has left when the pitcher and all infielders have left fair territory on their way to the bench or clubhouse.

First classify the appeal out

An appeal out can erase runs, but “third out” alone is not the whole test. Rules 5.08(a), 5.08 Comment and 5.09(d) require these checks:

• Batter-runner out before touching first: if that appeal is the third out, no run scores on the play.
• Force appeal as the third out: no run scores. A runner forced to advance who misses the forced-to base can still be retired there on appeal.
• Preceding runner out for a miss as the third out: no following runner scores. The upheld appeal is treated at the moment of the miss for those following runners.
• Non-force third out behind a run: this can be a time play. A legally completed run may count if it occurred before the third out, as in the OBR example where a tagged-up runner scores before another runner is retired returning to first.

The identity of the appealed runner, the base missed and whether a force still existed therefore matter more than the order in which players appear to cross home.

The defence may choose the advantageous out

Rule 5.09(c) recognizes an apparent “fourth out.” If a third out has already occurred during the play, the defence may still complete a timely appeal on another runner. When that sustained appeal changes whether a run counts, it takes precedence in determining the inning’s third out.

If there is more than one appeal on the inning-ending play, the defence may choose the out that gives it the advantage. This is not a literal fourth out added to the inning; it is a rule for selecting which out controls the score.

Appeal first, then challenge the ruling

MLB’s current Replay Review guidance lists whether a runner touched a base and whether a runner legally tagged up as reviewable calls. That does not remove the defence’s obligation to make the underlying OBR appeal. The fielding team first creates an appeal ruling; the manager or crew chief may then use the applicable replay procedure to review that ruling.

Replay review and a rules appeal are therefore different acts: the appeal asks the umpire to rule on a baserunning violation, while replay asks whether a reviewable on-field ruling was factually correct.

A home run runner misses first

Situation: the batter-runner misses first on a ball hit out of the park, then touches second before turning back.

MLB 2026 ruling: the runner may no longer correct first while the ball is dead. After the ball is put back in play, the defence can tag first and clearly appeal. If the appeal is timely, the runner is out under Rule 5.09(c)(2). The decisive fact is that the runner touched the next base during a dead ball before trying to correct the miss.

The runner is scrambling back to home

Situation: a runner slides past home without touching it, immediately turns back, and the catcher steps on the plate with the ball but never tags the runner.

MLB 2026 ruling: the base touch alone does not retire the runner. Because the runner is actively trying to return, Rule 5.09(b)(12) requires a tag of the runner. If the runner touches home first, the run scores.

A forced runner misses second with two out

Situation: with two outs and runners on first and third, the batter hits safely. The runner from first passes second without touching it, while the runner from third crosses home. Before the next pitch, the defence appeals at second.

MLB 2026 ruling: the appeal is the third out and no run scores. The runner from first was forced to second by the batter becoming a runner, so the upheld appeal is a force out within Rule 5.08(a).

An apparent third out does not save the run

Situation: with one out and runners on first and third, a fly ball is caught. The runner from third leaves before the first touch and crosses home. The runner from first is then tagged for the apparent third out. Before leaving fair territory, the defence appeals at third.

MLB 2026 ruling: the upheld appeal is the advantageous out under Rule 5.09(c), and the run is removed. The defence is entitled to have the appeal out control the inning even though three outs had appeared to occur already.

The defence waits through another pitch

Situation: a runner misses second and reaches third. The pitcher delivers to the next batter, then the defence asks to appeal second.

MLB 2026 ruling: the appeal is too late. Rule 5.09(c) closes the appeal window at the next pitch, so the missed base no longer supplies an appeal out.

How to rule any missed-base sequence

1. Name the code and season. This page’s baseline is MLB OBR 2026.
2. Identify the exact error. Missed base, early tag, failure to return to first, or missed home with no return attempt.
3. Separate automatic outs. Passing a runner and abandonment do not wait for this appeal process.
4. Check for correction. Track reverse-order retouches, following runners and whether the ball was dead.
5. Check the appeal mechanics. Live ball, secure possession, correct runner or base, and unmistakable intent.
6. Check the deadline. Next pitch, intervening play, appeal error or field departure may end the right.
7. Classify the out for scoring. Batter-runner before first, force, preceding-runner miss, time play or advantageous fourth out.
8. Only then consider replay. Review tests the appeal ruling; it does not create a missing appeal.

College procedure is similar, not identical

The 2025 and 2026 NCAA Baseball Rules, Rule 8-6, also use a live-ball base-running appeal and require the pitcher to take the pitching plate before “Play” is called after a dead ball. NCAA adds details that should not be silently imported into MLB:

• If obstruction causes the missed base, NCAA Rule 8-6(a) Note 4 bars an out on that missed-base appeal.
• If the defence errs during its first appeal attempt or a runner advances, NCAA generally removes the right to appeal any runner at any base, subject to its narrow live-ball misplay exception.
• NCAA’s definition of leaving the field for an inning-ending appeal also mentions the catcher leaving the catcher’s position, in addition to the pitcher and infielders leaving fair territory.

Those are NCAA 2025–26 provisions, not universal baseball rules. A school, youth, international or tournament game should be checked against the rulebook and local regulations appointed for that competition.

Five claims to avoid

• “The umpire saw the miss, so the runner is automatically out.” Not for the OBR appeal situations listed in Rule 5.09(c).
• “A verbal request during Time is enough.” The OBR baserunning appeal is completed with the ball in play.
• “An awarded base need not be touched.” Every intervening base still must be touched.
• “Every third-out appeal erases every run.” Force status, the batter-runner’s failure to reach first, runner order and timing decide that question.
• “Replay will discover the miss for the defence.” MLB replay can review a touch or tag-up ruling, but the defence must first make the rules appeal.

Governing-body sources and effective versions

• Office of the Commissioner of Baseball — 2026 Official Baseball Rules, Rules 5.06(b)(1), 5.06(b)(4)(I), 5.08, 5.09(b)–(d), Definitions of Terms and Appendix 6
• Major League Baseball — current Appeal Plays rules glossary
• Major League Baseball — current Replay Review guidance, specified baserunning calls and tag-ups
• NCAA — 2025 and 2026 Baseball Rules Book, Rule 8-6, “When Runners Are Out on Appeals”

Checked against the Office of the Commissioner’s 2026 OBR and MLB’s current appeal and replay guidance, plus NCAA Rule 8-6 for the labeled college comparison, on 25 August 2026. The MLB rules are the controlling baseline for this page; another competition’s appointed rulebook and local regulations may change the procedure.