The interactive online spell checker for SNOMED CT terms is based on the LACP method (see formula (1) at http://snomedct-spell-checker.com). The spell checker is a PHP script, which connects to a MySQL database containing the full set of unduplicated SNOMED CT terms extracted from the 2009AB edition of the UMLS knowledge source. The spell checker accepts an input query and interactively outputs the SNOMED CT terms satisfying the specified initial parameters. The spell checker returns a record set containing a Concept Unique Identifier (CUI) of a term, a term itself, a value of the parameter alpha (formula (2) at http://snomedct-spell-checker.com), and a value of LACP(S,T) defined in formula (1). The SNOMED CT Spell Checker offers three types of search: search with dynamically estimated parameters, search with static parameters, and search with user-defined parameters. The LACP method was introduced by the authors and is pending publication approval for the WISH 2011 workshop.