elastic-nest.cs

// See https://github.com/elastic/elasticsearch-net/issues/2860

public class MyDocument
{
    public string RecordType { get; set; }
}

var client = new ElasticClient();

client.Search<MyDocument>(s => s
    .Index("ic")
    .AllTypes()
    .Query(q => q
        .MatchPhrase(mp => mp
            .Field(f => f.RecordType)
            .Query("WealthEvent")
        )
    )
);