How to Get Insurance to Cover Drug or Alcohol Rehab

Insurance must cover addiction treatment by federal law, but carriers do not make the process easy. Between prior authorization, medical necessity reviews, network restrictions, and the sheer volume of paperwork involved, many families give up before they get to an approval. They should not. Under the Affordable Care Act (ACA) and the Mental Health Parity and Addiction Equity Act (MHPAEA), health insurers are legally required to cover substance use disorder treatment at the same level as other medical care. The steps below are the exact playbook that treatment facility admissions teams use every day to get inpatient rehab approved, and the same playbook you can use to fight a denial.

According to the Centers for Medicare & Medicaid Services (CMS), substance use disorder services are one of ten essential health benefits that all ACA marketplace plans must cover. The Department of Labor reports that MHPAEA parity enforcement has led to millions of dollars in recovered benefits for patients whose claims were initially denied. The catch: the law is only useful if you know how to apply it.

Step 1: Call the Behavioral Health Number on Your Card

Do not call main member services. Call the behavioral health or mental health line specifically — it routes to a team with the authority to verify substance use disorder benefits and issue prior authorization. The number is typically printed on the back of your insurance card, often labeled “Behavioral Health,” “Mental Health,” or the name of the behavioral health subsidiary.

Common behavioral health lines for major carriers:

• Aetna Behavioral Health: 1-800-424-3627
• Cigna Behavioral Health / Evernorth: 1-877-622-4327
• UnitedHealthcare / Optum: 1-855-204-4058
• Blue Cross Blue Shield: varies by state plan — ask for “BCBS Behavioral Health”

If you cannot find a behavioral health number on your card, call the general member services line and say: “Please transfer me to behavioral health benefits for substance use disorder verification.” General member services representatives typically do not have access to the detailed prior authorization systems that behavioral health teams use.

Step 2: Have These Items Ready Before You Call

Gathering this information in advance makes the call far more productive:

• Member ID number (front of card)
• Group number (front of card, if employer-sponsored plan)
• Name and NPI number of the specific facility you are considering — ask the facility for their NPI
• Your date of birth
• Estimated admission date
• The precise level of care — use the phrase “residential inpatient substance use disorder treatment” or “medical detoxification.” Vague requests produce vague answers.
• The diagnosis, if you have an assessment — for example, “alcohol use disorder, severe” or “opioid use disorder”

Facility admissions teams use this exact script every day. You can use the same one.

Step 3: Ask These Exact Questions

Write down every answer and the name of the representative you spoke with. Request a reference number for the call before hanging up. The seven questions that matter most:

1. “Is [facility name] in-network for my specific plan?”
2. “What is my individual deductible for behavioral health, and how much of it have I already met this year?”
3. “What is my coinsurance percentage for inpatient behavioral health?”
4. “Do I need prior authorization for inpatient admission?”
5. “What is my out-of-pocket maximum for behavioral health, and how much of it have I already met?”
6. “Is there any annual limit on the number of days covered for inpatient substance use treatment?”
7. “What ASAM level of care criteria do you use for medical necessity review?”

The last question matters more than most patients realize. The American Society of Addiction Medicine (ASAM) criteria are the clinical framework that most insurers use to decide whether residential treatment is justified. Knowing which version of ASAM your insurer uses helps your facility build a stronger authorization request.

Step 4: Request Prior Authorization Proactively

Most insurers require prior authorization (PA) for inpatient rehab. Without it, they can deny the claim retroactively — even after you have completed treatment. The facility’s admissions or utilization review team should handle prior auth on your behalf, but confirm this explicitly. Ask: “Will your team submit prior authorization before my admission date, and who specifically will handle it?”

Prior authorization requests are typically reviewed within 24 to 72 hours. According to the Department of Labor, insurers that fail to meet standard timeframes without valid reason may be in violation of ERISA requirements for group health plans. If the facility says prior authorization is not required, ask them to document that in writing or with a reference number from your insurer.

Step 5: Get Everything in Writing

Ask the insurance representative to send you a written summary of your behavioral health inpatient benefits. This protects you if the insurer later tries to deny a claim on coverage grounds. Also ask the facility to provide a written out-of-pocket estimate based on your verified benefits before you admit.

If the insurer refuses to send a written benefits summary, note the refusal in writing yourself, including the date, time, representative’s name, and reference number. This paper trail becomes essential if you later need to file an appeal or a parity complaint.

What to Do If Insurance Denies Your Rehab Claim

A denial is not the end. Federal law gives you the right to a full internal and external appeal process, and appeals succeed at a meaningful rate. According to a 2022 analysis by the American Psychiatric Association, external reviewers overturn mental health and substance use disorder denials in roughly 40 percent of cases when clinical documentation is properly submitted.

First, request the denial letter in writing and identify the specific reason. The four most common reasons, in rough order of frequency:

1. Not medically necessary — the insurer claims the requested level of care is not clinically justified.
2. Not meeting level of care criteria — similar, usually tied to ASAM criteria interpretation.
3. Out-of-network provider — the facility is not contracted with your plan.
4. Prior authorization not obtained — the admission was not pre-approved.

Each has a different appeal strategy, and each can be overturned.

How to Appeal a Medical Necessity Denial

A medical necessity denial is the most common type and the most winnable on appeal. Your doctor or the facility’s clinical team must write a letter documenting:

• The severity of the substance use disorder, mapped to DSM-5 criteria
• Withdrawal risk factors (especially for alcohol, benzodiazepines, and opioids)
• Co-occurring mental health conditions such as depression, anxiety, PTSD, or bipolar disorder
• Failed outpatient treatment attempts, if any — this strongly supports the need for a higher level of care
• Social determinants such as unstable housing, lack of sober support, or active triggers in the home environment
• The ASAM level of care assessment and why residential care is clinically required

Submit this letter with the facility’s clinical assessment. The National Institute on Drug Abuse (NIDA) has published materials emphasizing that documented clinical severity is the single strongest predictor of successful medical necessity appeals.

The Mental Health Parity Law Is Your Legal Protection

Under the Mental Health Parity and Addiction Equity Act, insurers cannot apply more restrictive limits on substance use disorder treatment than they apply to comparable medical or surgical care. If your plan covers unlimited days of inpatient medical care, it cannot cap inpatient rehab at 30 days. If your plan has a $200 per day copay for medical hospitalization, it cannot charge $400 per day for behavioral health hospitalization.

If a denial appears to violate parity, file a complaint with your state insurance commissioner alongside your internal appeal. State insurance departments have enforcement authority that can resolve cases faster than federal channels. For employer-sponsored plans, the U.S. Department of Labor Employee Benefits Security Administration (EBSA) accepts parity complaints directly. For a deeper explanation, see our guide to the Mental Health Parity Act.

External Review: Your Final Option

If your internal appeal is denied, federal law gives you the right to an external review by an independent review organization (IRO). The external reviewer has no financial relationship with your insurer, and their decision is binding on the insurer. External review is free to you, and the process must be completed within 45 to 60 days of your request. The facility’s patient advocate or a healthcare attorney can help you file. Do not skip this step. Many patients assume a first denial is final when it is actually the start of a process designed to correct errors.

Common Mistakes That Lead to Denials

A few common procedural mistakes cause avoidable denials:

• Admitting without prior authorization. Always get PA before the admission date unless the facility has confirmed in writing that it is not required.
• Going out of network without understanding the cost. Out-of-network care is covered at a much lower percentage — sometimes zero, for HMO plans.
• Not documenting failed outpatient attempts. If you have tried outpatient treatment before, document it — it strengthens medical necessity.
• Accepting a verbal denial. Always request the denial in writing. A verbal denial is not actionable for appeal.
• Missing appeal deadlines. Most plans give you 180 days to file an internal appeal. After that, your rights may be limited.

If You Do Not Have Insurance

The entire appeal process assumes you have a plan. If you are currently uninsured, the most effective step is to obtain coverage before treatment begins. ACA marketplace plans are available year-round for people who qualify for a Special Enrollment Period, and many people qualify without realizing it. A licensed health insurance specialist can walk you through enrollment quickly. For the cost implications of going without insurance, see our guide on rehab cost without insurance.

For help understanding what your specific plan covers, use our free cost calculator or see our does insurance cover drug rehab guide. For carrier-specific coverage details, see our Aetna rehab coverage page and other carrier guides.

Sources

• Centers for Medicare & Medicaid Services. “Mental Health Parity and Addiction Equity Act.” 2024.
• U.S. Department of Labor, Employee Benefits Security Administration. “MHPAEA Enforcement Fact Sheet.” 2024.
• American Society of Addiction Medicine (ASAM). “The ASAM Criteria.” 2024.
• American Psychiatric Association. “External Review Outcomes in Mental Health Parity Cases.” 2022.
• National Institute on Drug Abuse (NIDA). “Principles of Effective Treatment.” 2024.
• Healthcare.gov. “Appealing a Health Plan Decision.” 2026.