How to use Z codes

[ginnshaw]

I need advice on billing insurance for a pediatric speech and language office.  We have a client who has had a cleft lip and palate repair and still being treated for speech therapy.  Should I use the code that states personal history of cleft lip and palate repair (Z87.730), or should I use the code that states cleft lip and palate (Q37.9), along with my speech Dx code?
Thanks!!

[Michele]

I would put the speech dx code as primary and the history of  code as secondary.