The LCMS acknowledges the textual-critical evidence that Mark 16:9-20 does not appear in the oldest manuscripts and was likely a later addition to the Gospel. However, the LCMS receives the longer ending as part of the biblical canon and includes it in its Bibles with appropriate textual notation. LCMS doctrine affirms that the longer ending is biblical Scripture to be respected and used in the church, even if its original compositional history is uncertain.

LCMS textual and liturgical practice includes Mark 16:9-20 as canonical Scripture. The passage's content — the resurrection appearances, the Great Commission, signs and wonders — is consistent with and complementary to other Gospel accounts. LCMS teaching treats Mark 16:9-20 as authoritative Scripture for doctrine and practice.