Medical necessity and prior authorization

Medical necessity means a service is needed to diagnose or treat a condition. It also has to meet accepted standards of medicine. Prior authorization means your plan agrees, before care starts, that a service meets that bar. In Medicaid, it's the main way states and health plans check requests for applied behavior analysis (ABA) therapy.

For Medicaid, federal law doesn't define medical necessity, so each state sets its own rules. For children on Medicaid, each request must be judged on its own, and the review can't hold up needed care. An approval also isn't a promise that your plan will pay.

Before therapy starts, your Board Certified Behavior Analyst (BCBA) usually sends your plan a request. It often includes the diagnosis or diagnostic evaluation, the ABA assessment and a treatment plan. That plan lists the hours requested and the reasons for them. The review should come after the treatment plan is written and before therapy begins.

Each approval lasts for a set time. To renew it, your provider sends new progress data and an updated plan. This step is called reauthorization (approval for the next stretch of time). The Council of Autism Service Providers says approvals shouldn't usually last under six months, but Medicaid lets states set their own periods, and some are shorter.

• What goes in the request: Ask what will be sent to the plan and how the requested hours are explained.
• How long approval lasts: Ask how long your plan's approval runs and when the reauthorization paperwork is due.
• How scores are used: Ask how the plan will weigh test scores, since the same provider group says one score alone shouldn't be used to deny or end ABA.