Your contact was right — the 45-year search is real, though it comes from a regulation implementing the statute rather than the statute itself. Here's the breakdown:

The 45-year rule. Under 20 CSR 500-7.200 (which implements RSMo 381.071), before a title insurance policy is written, the insurer or its licensed agent must cause a search of the title based upon evidence prepared from a current set of records maintained to show all matters affecting the title for a continuous period of not less than the immediate past forty-five (45) years. That record set must be geographically indexed and encompass all properties in the county — i.e., a title plant. So yes: 45 years is the regulatory minimum search period for every policy you issue. One carve-out: an attorney licensed in Missouri isn't required to base an examination on geographically indexed records if they personally inspected the best title evidence available. Here is a reference for you: - Legal Information InstituteLegal Information Institute

Plats older than 45 years. The 45-year window is a floor, not a cutoff that erases older records. A subdivision plat recorded 60 or 80 years ago still creates easements, setbacks, and restrictions that run with the land — those are "matters affecting the title" and don't expire just because they predate your search window. Standard examination practice is to pull and review the plat (and any old restrictions/easements in the chain) regardless of its recording date, and to except to them in Schedule B. So don't treat the 45 years as permission to ignore an older plat.

Prior policies (starters). The regulation doesn't create an exception letting a prior policy substitute for the 45-year search requirement. In practice, underwriters commonly allow "starter" policies to shorten the examination work — you search from the prior policy date forward and rely on the starter for the earlier period — but whether and how you can do that is governed by your agency contract and your underwriter's guidelines, not by the regulation. Before adopting starters as a workflow, get your underwriter's written guidance, since you're the one certifying the search meets the regulatory standard.

One caveat: I'm not a lawyer yet (will be soon :-)), and since your license now rides on this, it's worth confirming your specific procedures with your underwriter and, if needed, the Missouri Department of Commerce and Insurance.