The general rule: tolled to age 21
Under RSMo § 516.170, if a person entitled to bring an action is under the age of 21, mentally incapacitated, or imprisoned on certain criminal charges at the time the cause of action accrued, that person may bring the action within the otherwise applicable time limit after the disability is removed. For an ordinary negligence or property claim, this means the five-year clock under § 516.120 generally doesn't start running until the minor's 21st birthday.
A genuinely litigated carve-out: malpractice is different
Here's where it gets distinctive. Section 516.170 opens with the phrase "except as provided in section 516.105" — and § 516.105, Missouri's medical malpractice statute, contains its own separate tolling language. Missouri courts, including in Hodges v. Southeast Missouri Hospital Association and Braswell v. Chehyal, have squarely held that this carve-out means a minor's tolling for a medical malpractice claim ends at age 18, not 21 — a full three years earlier than the general rule. One plaintiff who waited until exactly age 21 to refile, relying on the general tolling rule, found his malpractice claim barred because the two-year malpractice clock had actually started running at 18.
An even narrower rule for very young children
Section 516.105 goes further still for the youngest patients: a child under the age of 10 at the time of the alleged malpractice generally has only until their 12th birthday to file — not 18, and certainly not 21. This is a genuinely narrow window, worth flagging early in any case involving a young child and a medical provider.
Why this distinction matters so much
Because the general tolling rule and the malpractice-specific rule point to two different ages entirely, a family assuming the more generous age-21 rule applies to what is actually a malpractice claim could lose the right to sue years before they expected to. Confirming early whether a claim sounds in ordinary negligence or medical malpractice is a genuinely important first step in any Missouri case involving a minor.
The discovery rule: when damage isn't obvious right away
Separate from minors' tolling, Missouri law holds that a cause of action accrues when the damage resulting from the wrongful act is "capable of ascertainment" under RSMo § 516.100 — a discovery-oriented standard that can delay the start of the clock for injuries that aren't immediately apparent.
What doesn't pause the clock
A genuinely common and costly misunderstanding: actively negotiating a settlement with an insurance company does not toll or pause Missouri's filing deadline. The clock keeps running the entire time talks are ongoing, regardless of how close the parties seem to a resolution.