Please read the following from the HCA:

Attention Orthodontic Services Providers:

The current version of the Orthodontic Services Billing Guide, dated April 2019, has a typographical error on page 22. The expedited prior authorization (EPA) number for the initial placement of appliances and subsequent 3-month period should be 870000990. If you have billed using this EPA number and have received a denied claim, please rebill using the corrected EPA number.

HCA is currently revising the Orthodontic Services Guide and will publish it by August 1, 2019. This correction will be reflected in the revised guide.