Insurance terms for mental health treatment decide what you pay for therapy, PHP, IOP, detox and residential care. The deductible, copay, coinsurance and out-of-pocket maximum set your share of the cost. Prior authorization, medical necessity and network status decide whether the plan pays at all. This glossary defines each term in plain words, with an example from treatment.
Updated September 2026. Next review: September 2027.
Quick reference: insurance terms and what they mean
| Term | What it means | Example in treatment |
|---|---|---|
| Allowed amount | The most your plan will pay for a covered service, set by its contract with in-network providers | Your share of a PHP day is worked out from the allowed amount, not the program's list price |
| Appeal | A formal request asking your plan to change a decision to deny or limit coverage | You appeal when the plan approves fewer IOP days than your clinician recommends |
| Balance billing | A bill from an out-of-network provider for the difference between its charge and what the plan paid | An out-of-network therapist bills you for the part of the session fee the plan did not cover |
| Benefits verification | A check with your insurer that shows what your plan covers before care starts | Admissions calls your insurer to confirm your deductible and which levels of care are covered |
| Coinsurance | Your share of the allowed amount as a percentage, paid after the deductible | You pay a set percentage of each PHP day, and the plan pays the rest |
| Concurrent review | Regular check-ins where the plan reviews whether continued care is still needed | Your plan reviews progress during a residential stay before approving more days |
| Copay | A fixed amount you pay for a visit or a day of care | You pay the same amount for each outpatient therapy session |
| Deductible | What you pay for covered care each plan year before the plan starts paying | You pay the allowed cost of your first IOP sessions until the deductible is met |
| Explanation of benefits (EOB) | A statement from your plan showing what it paid and what you owe | The EOB for a detox stay lists the allowed amount, the plan's payment and your share |
| In-network | A provider with a contract with your plan, usually at lower cost to you | An in-network PHP program bills your plan at the contracted rate |
| Level of care | How much treatment and supervision you receive, from outpatient to residential | Your plan may approve PHP first and then IOP as you step down |
| Medical necessity | The plan's test of whether a service is needed for your condition | The plan checks your symptoms against its criteria before it approves residential care |
| Mental health parity | The rule that plans cannot limit mental health and addiction care more strictly than other medical care | A plan cannot cap therapy visits more tightly than it caps comparable medical visits |
| Out-of-network | A provider with no contract with your plan, usually at higher cost to you | Your plan pays less of an out-of-network program's charge, or nothing, depending on the plan |
| Out-of-pocket maximum | The most you pay for covered in-network care in a plan year | After you reach it, covered in-network care is paid in full for the rest of the year |
| Plan year | The 12 months your deductible and out-of-pocket maximum count toward | Your deductible resets at the start of the plan year, often in January |
| Premium | The amount you or your employer pay each month to keep the plan | Premiums are separate from what you pay when you use care |
| Prior authorization | Approval your plan must give before some care starts | The program asks your plan to approve PHP before your first day |
| Single case agreement | A one-time contract between a plan and an out-of-network provider for one patient | A plan agrees to pay an out-of-network program at in-network rates for your care |
| Utilization review | The plan's process for checking that care is needed and at the right level | A plan reviewer talks with your clinician about whether IOP is still the right level |
How do the deductible, copay and coinsurance work together?
These three terms decide what you pay at each point in the plan year. The deductible comes first, and the copay or coinsurance applies after it is met.
- 1Before the deductible is met, you usually pay the full allowed amount for covered care.
- 2After the deductible is met, you pay a copay or coinsurance, and the plan pays the rest.
- 3After the out-of-pocket maximum is reached, covered in-network care is paid in full until the plan year ends.
Some plans use a copay for outpatient therapy and coinsurance for PHP or residential care. Your benefits verification shows which one applies to each level of care.
What is prior authorization, and who asks for it?
Prior authorization is your plan's approval before a level of care starts. The treatment program usually asks for it, because the plan wants clinical details from the people who assessed you.
Plans often require prior authorization for PHP, IOP, detox and residential care, and less often for weekly therapy. When a plan approves care, it may approve a set number of days, then review your progress before it approves more.
What does medical necessity mean for mental health treatment?
Medical necessity means the plan agrees that a service is needed for your condition at that level of care. Plans compare your clinical information with written criteria, and the criteria must be applied to mental health care the same way as to other medical care.
A plan may decide that you need care but not at the level requested. It might approve IOP when PHP was recommended, for example, and your clinician can ask for a review of that decision.
What does mental health parity mean for your coverage?
Mental health parity is the federal rule that stops most health plans from limiting mental health and addiction care more strictly than other medical care. It covers visit limits, deductibles and copays, and the rules plans use to approve care.
Parity does not mean a plan must cover every program. It means the limits a plan uses for behavioral health treatment cannot be stricter than the limits it uses for comparable medical care.
How do you read an explanation of benefits?
An explanation of benefits is a statement from your plan, and it is not a bill. It lists each service, the amount the provider charged, the allowed amount, what the plan paid, and what you may owe.
Compare each EOB with the bill from your provider. If the amounts do not match, call your plan or the provider's billing team before you pay.
What can you do if your plan denies coverage?
You can ask your plan to explain the denial in writing and file an appeal. The treatment program can often help, because it can send the clinical records the plan needs.
In California, if the internal appeal does not resolve it, you can ask for an independent medical review. The Department of Managed Health Care handles most HMO and many PPO plans, and the California Department of Insurance handles the others, so check which one regulates your plan. Self-funded employer plans follow federal appeal rules instead, and your plan documents explain the steps.
How does in-network care change what you pay?
In-network providers have agreed rates with your plan, so your share is usually lower and billing is simpler. Out-of-network care can cost more, and some plans pay nothing for it outside an emergency.
Enhance Health Group is in network with most commercial insurance plans, and our page on whether insurance covers rehab lists some of the plans we accept. For a wider view of levels of care and county resources, see our Orange County mental health and addiction care guide.
How this glossary was put together
The Enhance Health Group team wrote this glossary in September 2026, based on how commercial health plans usually describe these terms. Your own plan documents are the final word on your coverage, and a benefits check is not a guarantee that a plan will approve care. We review the glossary every September.
If you want help with your own plan, call Enhance admissions at (714) 862-1907. Admissions can check your benefits and explain your deductible, your share of the cost and which levels of care your plan covers.
