H0001 and H0002: SUD Assessment and Admission Screening Codes
H0001 and H0002 sit at the front door of substance use treatment. One is the full assessment, the other is the screening that decides whether someone is eligible to be admitted at all. Billing the wrong one, or both on the same day where the state does not allow it, is one of the most common SUD intake denials.
Short answer
H0001 is "Alcohol and/or drug assessment," the comprehensive substance use assessment that informs diagnosis, level of care, and the treatment plan. H0002 is "Behavioral health screening to determine eligibility for admission to treatment program," a shorter screen that decides whether the person should be admitted. Neither descriptor sets a unit, so each state Medicaid program defines the unit, who may perform the service, and whether both can be billed for the same person.
What each code covers
| Code | Federal descriptor | Typical role |
|---|---|---|
| H0001 | Alcohol and/or drug assessment | Full SUD assessment at intake |
| H0002 | Behavioral health screening to determine eligibility for admission to treatment program | Pre-admission screen |
How they fit together
In programs that use both, H0002 comes first: a brief screen that answers whether this person belongs in this program. H0001 is the fuller assessment that follows, documenting substance use history, severity, and the information needed to place the person at a level of care, often using ASAM criteria. Many states only pay one of the two per episode, or only in specific program types, which is why the pairing produces denials.
Who bills them
Typically state-licensed or state-credentialed SUD professionals and licensed clinicians, inside programs the state has certified for substance use services. The exact credential list is state-defined. Some states route SUD assessments for Medicaid members through a separate administrator or managed care plan, so the payer on the claim matters as much as the code.
Common denials
- Both codes billed where only one is paid. Check whether your state allows a screen and an assessment for the same episode.
- Wrong code for the program. Some states expect 90791 or H0031 in mental health programs and H0001 only in certified SUD programs.
- Credential mismatch. The rendering clinician's credential is not on the state's list for the code.
- Missing program modifier. States that require HF (substance abuse program) or an age modifier deny claims without it. See licensure and program modifiers.
- Frequency limits. Repeat assessments within the state's window deny unless a change in condition is documented.
Related codes
In mental health programs the parallel code is H0031. For licensed clinicians billing CPT, the diagnostic evaluation is 90791. For intensive outpatient after admission, see H0015. The full map is in H codes in behavioral health.
Federal HCPCS descriptors only. Your state Medicaid manual and each managed care contract define who may render the service, unit rules, caps, and rates. Verify against current guidance before billing.
Frequently asked questions
What is the difference between H0001 and H0002?
H0001 is the full alcohol and/or drug assessment. H0002 is a behavioral health screening to determine eligibility for admission to a treatment program. The screen decides whether someone should be admitted; the assessment informs diagnosis, level of care, and the treatment plan.
Can H0001 and H0002 be billed on the same day?
It depends on your state. Some Medicaid programs pay only one per episode or require them on separate dates. Check your state manual and managed care contract before billing both.
What is the unit for H0001?
The federal descriptor does not define one. Each state sets it, most often per encounter, and some states use time-based units.
Who can bill H0001?
Typically state-credentialed SUD professionals or licensed clinicians working in a state-certified substance use program. The exact credential list is set by each state.
SUD intake codes, checked against your state's rules.
See Stable check each H-code claim against your state's credential, unit, and frequency rules before it goes out.
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