Substance abuse billing has more moving parts than almost any other specialty. The code sets are unique. The payer structure is different from standard commercial insurance. Federal confidentiality regulations add a compliance layer that standard HIPAA doesn’t cover. And the authorization logic for intensive outpatient and partial hospitalization programs trips up even experienced billers who’ve never worked in this space.
This guide covers what you need to know to bill substance abuse treatment correctly.
The Payer Structure in Substance Abuse Billing
The first thing most new billers get wrong is routing.
Most commercial insurance plans carve behavioral health benefits, including SUD treatment, out to a managed behavioral health organization. These are separate entities from the primary commercial insurer:
- United Healthcare routes to Optum Behavioral Health
- Cigna routes to Evernorth Behavioral Health
- Aetna routes to Aetna Behavioral Health
- BCBS plans route to various entities depending on the state and plan type
- Humana routes to Humana Behavioral Health
A claim submitted to the primary commercial insurer for SUD services will deny CO-109: not covered by this payer, services excluded. The claim must go to the carve-out entity. Getting the routing right before the first claim is submitted is non-negotiable.
42 CFR Part 2: What It Requires in Billing
42 CFR Part 2 is a federal confidentiality regulation specifically for substance use disorder treatment records. It is more restrictive than HIPAA in important ways.
Under 42 CFR Part 2, information that identifies a patient as having or being treated for a SUD cannot be disclosed without specific written consent from the patient. This includes disclosure to other treating providers, to insurers processing claims, and to government agencies.
For billing purposes, the practical requirements are:
- The patient must sign a specific 42 CFR Part 2 consent form authorizing disclosure of treatment information to their insurer for billing purposes. A standard HIPAA authorization is not sufficient.
- Claim submissions should not include SUD diagnostic codes or treatment information beyond what is necessary for processing and is covered by the consent.
- Secondary disclosures, such as sending claim information to a collection agency, require additional consent.
A billing team that doesn’t know 42 CFR Part 2 will include SUD diagnosis codes on claims without confirming consent. That’s a compliance violation, not a billing error.
ASAM Level of Care and Authorization
Managed behavioral health organizations use the American Society of Addiction Medicine criteria to authorize levels of care for SUD treatment. The six levels:
- Level 0.5: Early Intervention
- Level 1: Outpatient Services
- Level 2.1: Intensive Outpatient Program (IOP)
- Level 2.5: Partial Hospitalization Program (PHP)
- Level 3: Residential Treatment
- Level 4: Medically Managed Intensive Inpatient
Authorization is level-specific. An authorization for Level 1 outpatient does not cover Level 2.1 IOP. A patient who steps up from IOP to PHP requires a new authorization at the PHP level before the first PHP session is billed.
Missing this step generates a denial for every session billed above the authorized level. In a program where sessions happen daily, that can accumulate to a significant denied balance in a short time.
IOP Billing: Codes and Structure
Intensive outpatient programs typically run 3 hours per day, 3 to 5 days per week. The billing structure:
| Code | Description | Billing Unit |
|---|---|---|
| H0015 | Alcohol and/or drug services, intensive outpatient | Per diem or per hour depending on payer |
| 90853 | Group psychotherapy | Per session |
| 90837 | Individual psychotherapy, 53+ minutes | Per session |
| Revenue Code 0905 | Intensive outpatient services | Required for facility billing |
The interaction between H0015, the CPT therapy codes, and revenue code 0905 on a facility claim is where most billing errors occur. Submitting H0015 without the CPT component, or submitting CPT codes without H0015, generates a denial. Revenue codes are required when billing as a facility. Many IOP programs try to bill as professional and wonder why their claims deny.
PHP Billing: Codes and Structure
Partial hospitalization programs run 4 to 6 hours per day and are billed differently from IOP:
| Code | Description | Billing Unit |
|---|---|---|
| H2019 | Therapeutic behavioral services, per diem | Per day |
| 90853 | Group psychotherapy | Per session within the day |
| 90801/90792 | Psychiatric diagnostic evaluation | Per evaluation |
| Revenue Code 0912 | Partial hospitalization, less than 24 hours | Required for facility billing |
PHP billing uses H2019 per diem. Each day of PHP has a fixed per-diem rate with the specific services within the day billed using CPT codes. Revenue code 0912 is required for the facility component. Missing any of these elements causes the claim to deny.
Common Substance Abuse Billing Errors and How to Avoid Them
Routing to the Wrong Payer
Always verify the carve-out for each patient’s plan before submission. Carve-outs are not always the same even within the same commercial insurer. A United plan bought through an employer may route to Optum. A Medicare Advantage plan from United routes differently. Verify per patient, per plan.
Missing Revenue Codes on Facility Claims
IOP and PHP programs billing as a facility must include revenue codes. Claims submitted without revenue codes deny for incomplete billing information. Check your claim form setup in your EHR to confirm revenue codes are mapped to the correct service types.
Using Outpatient Therapy Codes for IOP Sessions
IOP sessions are not the same as individual outpatient therapy visits. You cannot bill 90837 alone for an IOP session and expect it to pay. The IOP structure requires H0015 plus the component services. Billers trained on outpatient therapy who move to IOP billing without additional training will generate this error consistently.
Billing Without ASAM-Authorized Level
Confirm the current authorized level before every billing period. ASAM authorizations typically cover 30 to 60 days. When the authorization expires, all sessions after the expiration deny until a new authorization is in place. Track authorization expiration dates by patient on a daily list.
Substance abuse billing done correctly produces consistent, predictable revenue. Done incorrectly, the denials accumulate quickly and the compliance exposure is real.
At Dr. Billerz, our behavioral health billing specialists are trained in all of the above before your first claim goes out. Start the 4-week free pilot with no contracts. Or book a 15-minute call to discuss your specific program’s billing setup.
Frequently Asked Questions
What is the difference between IOP and PHP billing?
IOP (Level 2.1) bills using H0015 per diem or per hour with component CPT codes and revenue code 0905. PHP (Level 2.5) bills H2019 per diem with component CPT codes and revenue code 0912. Both require a separate ASAM-level authorization. The per-diem rate is typically higher for PHP than IOP.
Do I need a different consent form for 42 CFR Part 2?
Yes. A standard HIPAA authorization does not satisfy 42 CFR Part 2 requirements. The consent must specifically authorize disclosure of SUD treatment information for billing purposes, name the recipient (the insurer), and include other elements required by the regulation. Use a form designed specifically for 42 CFR Part 2.
How long does prior authorization take for IOP or PHP?
Initial authorization for IOP or PHP typically takes 24 to 72 hours for urgent cases with most managed behavioral health organizations. Non-urgent authorizations take 3 to 5 business days. Plan accordingly. Starting a patient in IOP before authorization is obtained creates a significant financial risk if the authorization is denied.
Can I bill H0015 and 90837 on the same claim?
Yes, for IOP programs. H0015 covers the program services and is billed as the primary IOP code. 90837 or 90853 are billed alongside for the specific therapy services delivered within the IOP session. The combination is required for a complete IOP claim. H0015 alone without the component codes will underbill the session.