If you're running or planning an IOP or PHP program, H0001 is one of the first codes you'll bill — and one of the most audited, because it establishes medical necessity and level of care for substance use treatment under most payer policies.AAPC H0001HCPCS H0001 A botched assessment not only kills your reimbursement for that session, it can unravel the entire clinical justification for everything that comes after it.
This is the code that opens the door. Get it right.
What H0001 Actually Covers
H0001 is a HCPCS Level II code for alcohol and/or drug assessment, defined as a billable service for an alcohol and/or drug assessment under the Alcohol and Drug Abuse Treatment H0001–H2041 code range.AAPC H0001HCPCS range It is typically billed as a comprehensive clinical evaluation conducted at intake. Many payers treat this as a 60–90 minute face-to-face session, though Medicaid policies vary by state and some commercial insurers publish their own documentation standards in provider manuals.
The assessment is distinct from a psychiatric diagnostic evaluation (which would be billed under 90791), a separate CPT code for psychiatric diagnostic evaluation often used by psychiatrists or psychologists.GenHealth 90791 H0001 is specifically focused on substance use — its severity, patterns, history, and clinical impact — along with a resulting treatment plan.
Think of it as the clinical foundation your entire program is built on. Without a thorough, well-documented H0001, every subsequent session you bill is vulnerable to medical necessity review.
What Must Be Included in the Assessment
Patient History
This isn't a quick intake form. A defensible H0001 requires a comprehensive review of the patient's background, including:
Medical history relevant to substance use (liver function, infectious disease exposure, cardiac concerns).
Psychiatric history, including prior diagnoses, hospitalizations, and medication trials.
Social history — housing stability, employment, legal involvement, support systems.
Family history of substance use disorders or mental illness.
Previous treatment episodes, including what worked and what didn't.
If a patient has been through treatment three times before, that history should shape your current plan — and your documentation should reflect that you actually looked at it.
Substance Use Patterns
This is the clinical core of the H0001. You need a detailed picture of:
Substances used (primary and secondary).
Age of first use and pattern of escalation.
Current frequency and quantity.
Route of administration.
Last use.
Withdrawal risk (critical for level-of-care and medical necessity).
Functional impairment — how substance use is affecting work, relationships, and health.NIDA SUD overview
Using a validated screening tool here is a best practice if you want clean claims and defensible clinical decisions. The AUDIT (Alcohol Use Disorders Identification Test), DAST-10, or CAGE are widely used, validated tools for screening unhealthy alcohol and drug use in adults.AUDIT WHODAST-10 The ASAM Criteria dimensions are the framework many insurers expect you to be working within for level-of-care justification in substance use treatment.ASAM CriteriaASAM levels explainer
Diagnosis
The assessment should result in a DSM-5 diagnosis documenting the specific substance use disorder and its severity (mild, moderate, or severe), which is then coded using ICD-10-CM codes such as F10.20 for severe alcohol use disorder or F11.20 for severe opioid use disorder.DSM-5 SUDICD-10 CM This is what justifies medical necessity for IOP or PHP placement in most payer policies.
A diagnosis without supporting documentation is a claim waiting to be denied. Every diagnostic criterion you're applying should be evident in your assessment notes, with clear linkage between symptoms, impairment, and the chosen ICD-10-CM code.
Treatment Plan Development
The H0001 doesn't end with a diagnosis — it ends with a plan. Payers want to see that the assessment directly informed individualized treatment goals, aligned with the assessed ASAM dimensions and level of care.ASAM Criteria This means:
Problem list tied to the assessment findings.
Measurable, time-bound treatment goals.
Recommended level of care with clinical rationale.
Any referrals for co-occurring psychiatric care, medical clearance, or medication-assisted treatment (for example, buprenorphine or methadone for opioid use disorder).SAMHSA MOUD
A generic treatment plan that could apply to any patient is a red flag for auditors. Individualization is the whole point.
H0001 Reimbursement: What to Expect
Reimbursement for H0001 varies significantly by payer and state. State Medicaid fee schedules often set distinct rates for alcohol and drug assessment services under the H0001 code, and these can differ widely between programs.Texas DSHS codes Commercial insurers often reimburse higher than Medicaid for comparable behavioral health services, though many require prior authorization or apply post-payment medical necessity review for higher levels of care like IOP and PHP.CMS parity fact sheet
Some Medicaid managed care organizations (MCOs) carve out behavioral health benefits to specialized behavioral health plans — meaning you could be credentialed with the medical plan but still need to credential separately with the behavioral health carve-out, as described in many state Medicaid managed care contracts.CMS Medicaid managed care This catches a lot of new programs off guard.
H0001 is generally billed once per episode of care, not repeatedly, in line with how initial assessments are treated across the Alcohol and Drug Abuse Treatment H0001–H2041 code range.AAPC range If a patient leaves and returns after a significant gap (often defined in payer policies as 60–90 days or more), a new assessment may be billable — but you should verify this with your specific payer contracts and guidelines before you bill it.
H0001 vs. 90791: Know the Difference
A lot of new programs conflate these two codes, and it's a common audit trigger.
90791 is a psychiatric diagnostic evaluation — a CPT code for a comprehensive mental health intake, typically conducted by a psychiatrist, psychologist, or other qualified mental health professional.GenHealth 90791 It covers psychiatric history, mental status exam, and diagnostic formulation.
H0001 is specifically the substance use assessment under HCPCS. Some payers will allow both to be billed at intake if a co-occurring mental health condition is being simultaneously evaluated, but many won't, and some will bundle these services under one evaluation payment. Always check your payer policies before you double-bill.
In practical terms: if your clinical director is a LCSW or LPC doing a substance-focused intake, you're usually billing H0001 (subject to state and payer rules). If a psychiatrist is conducting a standalone psychiatric eval, that's 90791. When both happen in the same visit, you may need to separate the documentation clearly and verify payer rules on same-day billing and bundling.
Common Documentation Pitfalls That Trigger Denials
Vague substance use history. "Patient reports drinking alcohol regularly" doesn't cut it. Specify frequency, quantity, duration, and functional impact, consistent with best practices in SUD assessment.NIDA assessment
Missing DSM-5 criteria language. Your diagnosis needs to be defensible. Reference the specific criteria that support a mild, moderate, or severe SUD classification, and ensure they line up with the ICD-10 code you select.DSM-5 SUD
No clinical rationale for level of care. If you're recommending IOP, explain why. ASAM Criteria dimensions give you a framework — use them to tie risk, biomedical needs, motivation, relapse risk, and recovery environment to the recommended level of care.ASAM CriteriaASAM levels explainer
Template-driven treatment plans. Auditors have seen thousands of these. If your goals are identical across most of your patients, expect scrutiny around whether services are truly individualized, which is a core expectation in federal and state behavioral health regulations.SAMHSA treatment standards
Missing clinician credentials. H0001 must be conducted by a qualified professional — typically a licensed behavioral health clinician such as an LCSW, LPC, or substance use counselor credentialed under state rules.SAMHSA workforce The credential and licensure number should be in the note.
State-Specific Considerations
H0001 is a HCPCS code, so Medicaid policies govern how it's covered in your state, often through state plan amendments, provider manuals, and managed care contracts.Medicaid benefits Key things to verify:
Whether your state Medicaid program covers H0001 as a standalone billable service, or bundles it into a per-diem rate for IOP or residential.
Provider type and credential requirements for the clinician conducting the assessment.
Prior authorization requirements for the assessment and for ongoing treatment.
States with Medicaid managed care structures like California, Florida, and Texas route SUD services through different combinations of fee-for-service, managed care plans, and specialty behavioral health plans, which affects how H0001 is processed and who pays the claim.CMS Medicaid managed care In Medicaid expansion states, the number of adults eligible for SUD services increased substantially, raising overall volume and making accurate assessment billing more operationally important.KFF Medicaid expansion
FAQ
What credentials are required to bill H0001?
Requirements vary by state, but most Medicaid programs require the assessment to be conducted by a licensed behavioral health professional — such as an LCSW, LPC, or licensed alcohol and drug counselor — operating within their scope of practice.SAMHSA workforceState licensure example Some states allow certain licensed counselors to conduct assessments under clinical supervision. Always verify with your state Medicaid office and commercial payer contracts before credentialing staff for this service.
Can H0001 be billed via telehealth?
Many Medicaid programs expanded telehealth coverage for SUD assessments during the COVID-19 public health emergency and have kept at least some of those flexibilities, including coverage of audio-visual telehealth for behavioral health.CMS telehealth Commercial payers vary. You'll need to check each payer's telehealth billing policies and ensure you're using the appropriate place of service code and telehealth modifier (commonly GT or 95, as specified by payer).CMS telehealth list
Is H0001 billable the same day as other services?
Some payers allow H0001 to be billed on the same day as the first treatment session, while others treat the assessment as a standalone service and may bundle it if billed with therapy or IOP on the same date of service.Medicaid billing manuals When billing H0001 alongside other codes, ensure the documentation clearly delineates the assessment from treatment services to avoid bundling denials.
How long do I need to keep H0001 documentation?
Federal rules generally require providers to retain records related to Medicaid and Medicare claims for at least six years, and some guidance and legal analyses recommend up to ten years to account for False Claims Act statutes of limitation.HHS record guidanceO&A FCA retention Many states impose longer retention periods in statute or regulation. For SUD programs specifically, audit risk extends well beyond the date of service — maintain documentation with that in mind.
What ICD-10 codes pair with H0001?
H0001 should be paired with the appropriate DSM-5/ICD-10 SUD diagnosis code — for example, F10.20 for alcohol use disorder, severe, or F11.20 for opioid use disorder, severe.ICD-10 CM The specificity of your diagnosis code should match the severity documented in your assessment.
Do I need a separate assessment for co-occurring mental health conditions?
H0001 covers substance use assessment specifically. If a co-occurring psychiatric condition is also being formally evaluated, that typically warrants a separate diagnostic evaluation (90791 or 90792) when allowed by payer policy, with clear documentation separating the SUD and psychiatric evaluations.GenHealth 90791 Always verify your payer's bundling and same-day service rules.
Working With ForwardCare
ForwardCare is a behavioral health MSO (Management Services Organization) that partners with clinicians, sober living operators, healthcare entrepreneurs, and investors to launch and scale behavioral health treatment centers. We handle the business side — licensing support, insurance credentialing, billing, compliance, and operational infrastructure — so our partners can focus on growth and clinical quality.
If you’re serious about opening or expanding a behavioral health treatment center but don’t want to navigate the business side alone, ForwardCare may be worth a conversation.
