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If you’ve ever had a substance abuse claim denied with a CO-4 (procedure not covered) or a CO-11 (medical necessity), you already know: SUD billing isn’t like other behavioral health billing. It’s its own specialty within a specialty with its own code set, its own payer quirks, its own documentation requirements, and its own set of denial traps that can quietly drain a treatment center’s revenue for months before anyone notices.
This guide is written for SUD treatment center directors, clinical staff, billing managers, and practice owners who are tired of being either denied or underbilling frequently, without knowing which is happening. We’re going to cover every major substance abuse billing code category, explain the rules that govern each one, flag the mistakes providers make most often, and give you the framework to bill more accurately, more completely, and with fewer rework cycles.
Why Substance Abuse Billing Is Uniquely Difficult?
It’s worth naming this plainly before we get into codes: substance use disorder billing is among the most complex and denial-prone areas in behavioral health. Not because providers are doing something wrong, but because the coding and payer environment is genuinely difficult.
The Coding Complexity That Most Billing Teams Aren't Trained For
SUD billing draws from three separate code sets that often overlap depending on the payer, the level of care, and the service type:
- CPT codes (developed by the AMA) are used for psychotherapy, psychiatric evaluations, and screening services
- HCPCS H-codes (developed by CMS for Medicaid) are a parallel code set that covers SUD-specific services that CPT doesn’t adequately capture: detox, residential, IOP, counseling, and methadone administration
- HCPCS G-codes used specifically for medication-assisted treatment (MAT/MOUD) services under Medicare and increasingly under commercial plans
The problem: not all payers accept all three. A commercial plan might pay CPT codes but not H-codes. A state Medicaid program might require H-codes for IOP and refuse CPT codes entirely. Billing the wrong code set for the wrong payer isn’t a minor mistake; it’s an immediate denial that often comes with a timely filing clock ticking in the background.
Carve-outs, MBHO Routing, And Why Claims Go To The Wrong Place
In addition to the code complexity, many commercial payers have carved out behavioral health and SUD benefits to separate managed behavioral health organizations (MBHOs), such as Optum Behavioral Health, Carelon Behavioral Health (formerly Beacon Health Options), and Magellan Federal, among others.
This means that even when a provider is credentialed with Aetna or Cigna, their SUD claims may need to be routed to Optum or Carelon, a different claims address, different prior authorization requirements, and often different accepted codes. Sending claims to the wrong entity is one of the most common SUD billing errors in treatment centers without dedicated billing staff.
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The SUD Billing Code Landscape: An Overview
What's The Difference Between CPT and HCPCS Codes in SUD Billing?
CPT codes (Current Procedural Terminology) are maintained by the American Medical Association and are the standard code set for most medical and behavioral health services in the U.S. For SUD providers, the relevant CPT codes cover individual and group psychotherapy (90832–90853), psychiatric evaluation (90791), and screening + brief intervention (99408, 99409).
HCPCS Level II H-codes (Healthcare Common Procedure Coding System) are maintained by CMS and fill in the gaps where CPT codes don’t exist. H-codes were developed to capture SUD-specific services, such as detox, residential treatment, IOP, methadone administration, and SUD counseling. They’re required by Medicaid in most states and accepted by many commercial plans.
HCPCS G-codes are a subset of HCPCS Level II codes used primarily for MAT (medication-assisted treatment) services under Medicare and increasingly under commercial payers.
The practical rule of thumb: always check payer-specific billing guides before coding. What works for one payer may be invalid for another.
How Do Medicaid Vs. Commercial Payers Handle SUD Codes Differently?
| Factor | Medicaid | Commercial (MBHO) |
|---|---|---|
| Code preference | H-codes typically required | Often prefer CPT; some accept H-codes |
| Prior auth | Required for most levels of care | Required; rules vary by MBHO |
| Level of care criteria | ASAM criteria + state-specific criteria | Payer's proprietary LOC criteria |
| Residential billing | Per diem, H0018/H0019 | Per diem or case rate, depending on contract |
| Group therapy units | Typically H0005 or 90853 | Payer-specific |
| MAT billing | State-specific OTP rules | G-codes or CPT E&M with add-on codes |
CPT Codes for Substance Abuse Treatment
CPT codes apply in SUD settings wherever licensed clinical professionals provide direct therapy, evaluation, or crisis services. Here’s what you need to know for each.
Individual and Group Psychotherapy Codes Used in SUD Settings
These are the standard mental health psychotherapy codes, but they’re commonly used in SUD outpatient settings by licensed counselors, therapists, and psychologists:
| CPT Code | Service | Time Requirement |
|---|---|---|
| 90832 | Individual psychotherapy | 16–37 minutes |
| 90834 | Individual psychotherapy | 38–52 minutes |
| 90837 | Individual psychotherapy | 53+ minutes |
| 90846 | Family therapy without the patient | No time minimum (session must be documented) |
| 90847 | Family therapy with the patient | No time minimum |
| 90853 | Group psychotherapy | No specified minimum, but the session must be documented |
Critical rule for SUD settings using 90837: This is a time-based code. Documentation must reflect total face-to-face time or start/stop times. In a SUD treatment setting, it’s very common for sessions to be 45–50 minutes (which should be billed as 90834, not 90837). Upcoding this even accidentally is an audit risk.
For group therapy (90853): Each patient in the group is billed individually under their own claim, one unit of 90853 per patient per session. This is a persistent point of confusion for billing staff new to behavioral health. You do not bill multiple units per patient for a single group session.
Psychiatric Diagnostic Evaluation (90791) in SUD Contexts
90791 is used for the initial psychiatric diagnostic evaluation, the intake assessment conducted by a licensed clinician (LCSW, LPC, psychologist, psychiatrist). In SUD settings, this maps to the comprehensive psychosocial assessment required at admission.
Important: Some payers distinguish 90791 (without medical services) from 90792 (with medical services, typically billed by psychiatrists or prescribers). Many SUD treatment centers bill 90791 when a prescriber performs the evaluation, which is a coding error and a potential audit trigger.
SBIRT Billing Codes: 99408 and 99409 Explained
SBIRT stands for Screening, Brief Intervention, and Referral to Treatment, a standardized approach to identifying and addressing alcohol and substance misuse. It’s reimbursable by Medicare, Medicaid, and most commercial plans, and yet it’s one of the most consistently underbilled services in SUD settings.
| Code | Service | Time |
|---|---|---|
| 99408 | Alcohol and/or substance abuse structured screening and brief intervention | 15–30 minutes |
| 99409 | Alcohol and/or substance abuse structured screening and brief intervention | >30 minutes |
Why this is underbilled: Many SUD programs conduct SBIRT as part of their standard intake process, but never bill for it because staff don’t realize it’s a separately billable service. For a treatment center seeing 30 new patients per month, not billing 99408 routinely is a significant monthly revenue leak.
Documentation requirement: Must use a validated screening tool (AUDIT, DAST, CAGE-AID, or similar). Document the tool used, the score, and the brief intervention provided.
Crisis Psychotherapy: 90839 and 90840
| Code | Service | Time |
|---|---|---|
| 90839 | Crisis psychotherapy, first 30–74 minutes | High documentation threshold |
| 90840 | Crisis psychotherapy, each additional 30 minutes | >Add-on to 90839 |
SUD providers who offer crisis intervention services, particularly outpatient and IOP programs, can bill 90839 when a patient presents in active psychiatric or substance-related crisis requiring immediate intervention. The documentation threshold is high: you must clearly establish that the session was unplanned, the patient was in crisis, and a focused clinical intervention was provided.
HCPCS H-Codes for Substance Use Disorder Services
H-codes are the backbone of SUD billing for programs treating Medicaid patients and for any level of care that goes beyond outpatient individual therapy. Here’s a breakdown of the codes that matter most:
H0001 — Alcohol and/or Drug Assessment
What it covers: A comprehensive assessment to determine a patient’s level of substance use, history, and appropriate level of care. Typically maps to an ASAM assessment or comprehensive psychosocial evaluation.
Billed by: Licensed counselors, psychologists, social workers
Units: Per assessment (typically 1 unit = the full assessment, though some states bill by 15-minute increments)
Common error: Billing both H0001 and 90791 for the same encounter. These codes describe similar services. Payer-specific guidance determines whether appropriate for billing on the same day, which is typically a duplicate claim.
H0004 — Behavioral Health Counseling and Therapy
What it covers: Individual behavioral health counseling or therapy services in a SUD treatment context. Used in states where Medicaid prefers H-codes over CPT codes for SUD counseling.
Key distinction from CPT: H0004 is not time-based in the same way that 90832/90834/90837 are. It’s typically billed by the unit (15 minutes per unit) in most state Medicaid programs.
Common error: Mixing H0004 and 90837 billing on the same plan without confirming payer preference. Some Medicaid plans that require H0004 will deny 90837 for the same service, and vice versa.
H0005 — Alcohol and/or Drug Services: Group Counseling
What it covers: Group counseling in a SUD treatment setting. The Medicaid equivalent of CPT 90853 in states that use H-codes.
Units: Typically billed per session per patient, though some states use 15-minute unit billing
Common error: Using 90853 when the payer requires H0005 (particularly on Medicaid claims). Also: billing multiple units per patient per group session when the payer requires one unit.
H0010 — Sub-Acute Detoxification
What it covers: Medically monitored detoxification services in a non-hospital setting. Typically billed as a per diem.
Documentation requirement: Daily nursing notes, vital signs, medication administration records, and physician/NP oversight documentation
Critical payer rule: Requires prior authorization with virtually every payer. Missing or lapsed authorization = immediate denial. This is one of the most common revenue losses at detox facilities.
H0011 — Acute Detoxification (Medically Managed)
What it covers: Hospital-based or acute medically managed detoxification. Higher acuity than H0010.
Billing model: Per diem billed daily for each day of medically managed detox
Documentation requirement: Same as H0010 but with more intensive physician documentation. Daily progress notes must reflect the medical necessity for continued acute level of care.
H0015 — Alcohol and/or Drug Services: Intensive Outpatient (IOP)
What it covers: IOP-level SUD treatment typically includes 9+ hours per week of structured services. This is one of the most commonly billed and most commonly under-billed codes in SUD treatment.
Billing models:
- Per diem: One daily rate regardless of how many services are delivered that day
- Per service: Bill each service (group, individual, case management) separately
- Per unit (15-minute): Some Medicaid programs bill H0015 by 15-minute units
The under-billing trap: Many IOP programs bill a flat H0015 per diem when the payer actually reimburses per service, meaning they’re leaving reimbursement for individual therapy sessions, case management, and skills groups on the table. Confirm your billing model with each payer’s billing guide.
S9480 vs. H0015: Some commercial payers use S9480 for IOP billing instead of H0015. Always verify billing H0015 to a payer that requires S9480 will result in a denial.
H0018 — Behavioral Health: Short-Term Residential
What it covers: Short-term residential SUD treatment, typically 30 days or fewer. Billed as a per diem.
Per diem components: The daily rate is meant to bundle room, board, and treatment services. Some payers allow unbundling of specific clinical services; many do not. Check payer contracts before billing individual services on top of the residential per diem.
Common mistake: Billing individual therapy or group sessions separately on top of H0018 without confirming the payer allows unbundled service billing on residential claims. Double-billing allegations are a serious compliance risk.
H0019 — Behavioral Health: Long-Term Residential
What it covers: Long-term residential SUD treatment, typically more than 30 days. Also billed as a per diem.
Common issues: Long-term residential is often only covered by Medicaid (rarely by commercial plans at full residential rates). Many commercial plans have a benefit limit review the EOB for benefit exhaustion denials, and know when to step down to IOP for billing purposes.
H0020 — Alcohol and/or Drug Services: Methadone Administration
What it covers: Methadone maintenance treatment administered at an Opioid Treatment Program (OTP). Billed per dose administered.
OTP billing is distinct: Medicare bundles all OTP services (counseling, toxicology, doses) into a weekly bundled payment under HCPCS code G2067 (initial) and G2068 (ongoing). Medicaid programs have their own per-dose and per-week billing rules. Commercial plans vary significantly.
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MAT Billing Codes: Medication-Assisted Treatment
MAT billing is its own ecosystem, and it’s gotten significantly more complex since Medicare launched its OTP bundled payment model and since the buprenorphine X-waiver was eliminated in January 2023.
G2067 Through G2080 — MOUD/MAT HCPCS Codes Explained
These codes were created by CMS for Medicare billing of opioid treatment program (OTP) services. They’re increasingly referenced by commercial payers as well.
| Code | Description |
|---|---|
| G2067 | Methadone — OTP intake (bundled) |
| G2068 | Methadone — weekly OTP bundle (counseling + doses + toxicology) |
| G2069 | Buprenorphine/naloxone — OTP weekly bundle |
| G2070 | Buprenorphine — OTP weekly bundle (without naloxone) |
| G2071 | Crisis psychotherapy, each additional 30 minutes |
| G2072 | Naltrexone — OTP monthly injectable |
| G2074 | OTP — additional counseling (beyond bundle) |
| G2075 | OTP — toxicology beyond what's included in bundle |
| G2080 | OTP take-home supplies |
Key concept — the OTP bundle: Under Medicare, most OTP services are bundled into a weekly payment. Billing individual counseling sessions separately on top of the bundle (except G2074 for additional counseling beyond the bundle threshold) is a billing error that triggers overpayment recoupment.
How to Bill for Office-Based Buprenorphine Prescribing (OBOT)?
For office-based opioid treatment (OBOT), a prescribing physician or NP treating opioid use disorder with buprenorphine in an outpatient setting (not a licensed OTP), the billing model is different:
- E&M visit: 99213–99215 based on complexity and time
- Drug screen: 80305, 80306, 80307 for presumptive toxicology; 80320+ for definitive confirmation
- Buprenorphine prescription: Billed through pharmacy benefit (not the medical claim)
Counseling: If the prescriber provides counseling during the same visit beyond what’s included in the E&M, the add-on psychotherapy codes (90833, 90836, 90838) may apply
What Changed After The X-Waiver Was Eliminated?
In January 2023, the X-waiver requirement for buprenorphine prescribing was eliminated as part of the Consolidated Appropriations Act. Any DEA-licensed prescriber can now prescribe buprenorphine for opioid use disorder without separate waiver training.
Billing implication: More prescribers are now eligible to bill for buprenorphine prescribing in an office-based setting. If you’re a behavioral health prescriber who recently started prescribing buprenorphine, make sure your credentialing with commercial payers reflects your updated scope of practice and that your billing reflects the appropriate E&M complexity for MAT management visits.
IOP, PHP, and Residential Billing: Level of Care Coding
What ASAM Criteria Mean For Your Billing Documentation?
The American Society of Addiction Medicine (ASAM) criteria are the standard framework for determining the appropriate level of care in SUD treatment. Most payers and virtually all managed care organizations require ASAM level of care documentation to support prior authorization and claims.
The 6 ASAM dimensions:
- Acute intoxication and/or withdrawal potential
- Biomedical conditions and complications
- Emotional, behavioral, or cognitive conditions and complications
- Readiness to change
- Relapse, continued use, or continued problem potential
- Recovery/living environment
Why this matters for billing: If your clinical notes don’t reference ASAM criteria and document the specific dimensions supporting the level of care, medical necessity denials become far more likely. Payers will request clinical documentation, and if reviewers can’t find ASAM-consistent documentation, they’ll downcode or deny regardless of whether the level of care was clinically appropriate.
IOP Billing: H0015, S9480, and the Per Diem vs. Per Service Question
| Code | Used By |
|---|---|
| H0015 | Medicaid — most states |
| S9480 | Some commercial payers (BCBS, Aetna, UHC plans) |
| 90853 (group) + 90837 (individual) | Some commercial payers that use CPT-based IOP billing |
The right code depends entirely on the payer. The billing structure (per diem vs. per service) also depends on your contract and the payer’s billing guide. Both are legitimate, but mixing them up leads to either denials or underpayment.
Standard IOP prior auth requirements:
- ASAM Level 2.1 documentation
- Initial authorization typically covers 2–4 weeks
- Concurrent review required for extension
- Clinical records must support continued medical necessity at each review
PHP Billing: H0035 and S9484
| Code | Used By |
|---|---|
| H0035 | Partial hospitalization — Medicaid |
| S9484 | Partial hospitalization — commercial payers (some) |
| 90853 + additional CPT codes | Some commercial PHP programs charge per service |
PHP (Partial Hospitalization Program) is typically ASAM Level 2.5, more intensive than IOP, typically 20+ hours per week, with psychiatric oversight. Documentation requirements are higher than IOP because the level of care is higher expect active physician/NP notes, medication management documentation, and multi-disciplinary treatment planning.
Residential Treatment: H0018, H0019, and Per Diem Billing
For residential SUD treatment, the revenue cycle is built around per diem rates. Everything hinges on:
- Valid prior authorization before admission (retroactive denials in residential are devastating)
- Concurrent review documentation at every required interval
- Discharge planning documentation that supports the level of care through the last covered day
- Step-down planning that supports the treatment trajectory
A note on Medicaid residential for adults: The Medicaid IMD exclusion (Institution for Mental Diseases exclusion) historically blocked Medicaid funding for most residential SUD treatment in facilities with more than 16 beds. This has been shifting significantly in recent years through Section 1115 waiver approvals in many states, but the rules are state-specific. If you’re a residential SUD treatment provider accepting Medicaid, know your state’s waiver status.
Place of Service Codes That Matter in SUD Billing
| POS Code | Setting | Common Use |
|---|---|---|
| 11 | Office | Outpatient SUD counseling, OBOT prescribing |
| 53 | Community Mental Health Center | SUD outpatient programs at CMHC sites |
| 57 | Non-residential substance abuse facility | OTP/methadone clinic |
| 58 | Non-residential opioid treatment facility | OBOT/buprenorphine prescribing setting |
| 72 | Rural health clinic | SUD services in rural settings |
| 32 | Nursing facility | SUD services for nursing home residents |
| 21 | Inpatient hospital | Acute medically managed detox |
Place of service errors are more costly than most providers realize. An IOP claim billed with POS 11 (office) instead of POS 53 or 57 may be denied or reimbursed at the wrong rate. A residential claim with the wrong POS can trigger a payer audit.
Common Substance Abuse Billing Mistakes (And How to Avoid Them)
Using Psychotherapy CPT Codes When HCPCS H-codes Are Required
This is the most common mistake for programs that started in Medicaid and hired billing staff trained on commercial/CPT-based billing, or vice versa. Each payer has a preferred code set for SUD services. Billing 90837 to a Medicaid plan that requires H0004 will result in a CO-4 denial (procedure not covered) every time.
Fix: Create a payer-specific billing reference sheet that documents which code set (CPT vs. H-code) each payer requires for each service type. Verify at enrollment and update annually.
Underbilling IOP: Missing Units And The Wrong Per Diem Structure
IOP under-billing is rampant. It happens in two ways: (1) billing a flat daily per diem to a payer that actually pays per service, leaving individual therapy and case management reimbursement unclaimed, or (2) billing per service to a payer that expects a per diem and creating a claims adjudication nightmare.
Fix: Pull the payer’s billing guide for IOP specifically. If you can’t find it, call the provider relations line and ask directly: “Do you pay IOP per diem or per service, and which code do you require?”
Missing Or Inaccurate ASAM Level Of Care Documentation
Payers don’t just want to know what you billed. They want to know why the patient needed that level of care on that specific day. If your clinical notes don’t reflect ASAM dimension documentation supporting the billed level of care, concurrent review denials will follow.
Fix: Build ASAM documentation prompts directly into your EHR clinical note templates. It doesn’t have to be elaborate; a brief, structured section addressing each dimension in the context of the clinical encounter is sufficient.
MAT Billing Errors: Wrong G-code, Wrong Modifier, Wrong Bundling Rules
Billing individual counseling sessions on top of the G2068 weekly OTP bundle (when additional counseling beyond the included threshold hasn’t been documented) is one of the most common MAT billing errors and one of the most risky from a compliance standpoint.
Fix: Map your MAT billing workflow to the OTP bundle documentation. Track which services are included in the weekly bundle vs. billable separately. Create a clear internal policy for when G2074 (additional counseling) applies.
Group Therapy Billing: The "One Unit Per Patient Per Session" Rule
Group billing confuses the billing staff regularly. The rule is simple but easy to miss: for group therapy (90853, H0005), you bill one unit per patient. If you have 8 patients in a group session, you submit 8 separate claims, one per patient, each for one unit of 90853. You do not bill 8 units on a single claim.
Timely Filing Misses Due To Authorization Gaps
SUD services require prior authorization from virtually every payer. When authorizations expire and aren’t renewed, or when a patient starts a new level of care before authorization is confirmed, claims get denied. The timely filing clock starts from the date of service, not the date the authorization issue was discovered.
Fix: Build authorization tracking into your billing workflow with automatic alerts for approaching expiration dates. Every SUD program with more than 10 active patients needs a systematic authorization management process.
Medicaid vs. Commercial Payer Differences in SUD Billing
Billing substance abuse services to Medicaid and commercial payers requires genuinely different approaches. Here’s a practical summary:
| Factor | Medicaid | Commercial |
|---|---|---|
| Code set | H-codes typically required | CPT preferred; some accept H-codes |
| Level of care criteria | ASAM + state-specific criteria | Proprietary criteria (often more restrictive) |
| Residential coverage | Covered in most states (with waiver) | Limited; often capped in days or dollars |
| IOP billing model | H0015, per diem or per unit | S9480, H0015, or CPT per service |
| MAT coverage | Usually covered; varies by state | Usually covered; G-codes or E&M-based |
| Prior auth burden | High | High (often higher for commercial MBHOs) |
| Parity protections | MHPAEA applies to state Medicaid | Full MHPAEA protections apply |
The parity angle: If your commercial payer is applying more restrictive utilization management criteria to SUD treatment than to equivalent medical/surgical benefits, that may be a parity violation under MHPAEA. This includes things like requiring more frequent concurrent reviews, applying shorter benefit days, or denying coverage for residential treatment while covering equivalent medical bed days. Parity violations are challengeable and, in many cases, successfully appealed with the right documentation.
Documentation Requirements That Protect Your Claims
For every level of care, your documentation needs to answer three questions a payer reviewer will ask:
- Why did this patient need this specific level of care on this specific date? (Medical necessity ASAM-based)
- What services were provided, by whom, and for how long? (Service documentation)
- What is the treatment plan, and how is the patient progressing? (Clinical trajectory)
The minimum documentation floor for each level:
Outpatient SUD counseling: Initial assessment (H0001 or 90791), individualized treatment plan, progress notes for each session documenting the presenting issue, intervention, patient response, and plan
IOP (H0015): All of the above, plus daily group attendance records, weekly treatment plan updates, and concurrent review documentation at each authorization interval
Residential (H0018/H0019): All of the above, plus daily nursing/clinical notes, medication administration records, physician oversight documentation, and discharge planning records beginning at admission
MAT (G2067–G2080): Consent for treatment, PDMP check documentation, toxicology results, prescription records, and counseling session notes
Documentation failures are one of the top two reasons SUD claims get denied on audit (the other being authorization gaps). A well-documented claim that’s denied can almost always be appealed successfully. A poorly documented claim that’s initially paid is a liability if the payer ever audits.
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Frequently Asked Questions
What CPT codes are used for substance abuse treatment?
The most commonly used CPT codes for substance abuse treatment include: 90791 (psychiatric diagnostic evaluation/intake assessment), 90832, 90834, and 90837 (individual psychotherapy by time), 90853 (group psychotherapy), 99408 and 99409 (alcohol/substance misuse screening and brief intervention — SBIRT), and 90839/90840 (crisis psychotherapy). In settings that bill Medicaid, HCPCS H-codes (H0001, H0004, H0005, H0015, etc.) are often required instead of or in addition to CPT codes.
What is the HCPCS code for intensive outpatient substance abuse treatment?
H0015 is the primary HCPCS code for intensive outpatient substance abuse treatment. Some commercial payers require S9480. Always verify the correct code and billing structure with your specific payer before submitting IOP claims.
What billing codes are used for medication-assisted treatment (MAT)?
Medicare OTPs use G-codes: G2067 (intake), G2068 (methadone), G2069 (buprenorphine), and G2071–G2072 (naltrexone). Medicaid OTPs use H0020 for methadone. Office-based buprenorphine prescribers bill E&M codes (99213–99215), with medication billed through pharmacy benefits.
How do you bill for IOP (intensive outpatient program) substance abuse treatment?
Bill H0015 for Medicaid (per diem or per 15-minute unit), S9480 for some commercial payers, or CPT codes (90853 for group, 90837 for individual) for others. Prior authorization is almost always required, and documentation must support ASAM Level 2.1 or higher.
What is the difference between H0018 and H0019 billing codes?
H0018 covers short-term residential SUD treatment (30 days or fewer). H0019 covers long-term residential treatment (more than 30 days). Both are billed per diem, one unit per day. Medical necessity must be documented at each review interval.
What is SBIRT billing, and how do I use codes 99408 and 99409?
99408 covers a 15–30 minute substance misuse screening and brief intervention. 99409 covers more than 30 minutes. Use a validated tool (AUDIT, DAST, CAGE-AID), document the score and intervention, and bill under the eligible provider’s NPI. These codes are widely under-billed in SUD settings.
What is the IMD exclusion and how does it affect Medicaid SUD billing?
The IMD exclusion bars Medicaid payment for adults in mental health or SUD residential facilities with more than 16 beds. Many states have obtained Section 1115 waivers allowing Medicaid to cover larger residential SUD programs. Check your state’s current waiver status if you operate a facility with over 16 beds.
Why are substance abuse claims commonly denied?
Top denial reasons include: missing or expired prior authorization, insufficient medical necessity documentation, wrong code set for the payer, incorrect place of service, missing ASAM level of care, timely filing violations, credentialing gaps with MBHO carve-outs, and unbundling OTP services that should be billed as weekly bundles.