Have a patient who is 29 days old at time of service. Diagnosed with K21.9 GERD, R19.7 diarrhea unspecified, and L22 diaper dermatitis. Insurance is denying due to dx not matching child's age. Not sure which code they are denying. I think it may be the diarrhea which may need to changed to P78.3 neonatal diarrhea but I really need some help on which dx you think they are denying or if I am correct. PLEASE HELP!! Thanks!