Colorado Medicaid: Requesting 2:1 Services (Without 0373T)

Last updated: July 21, 2026

2:1 staffing (two BTs supporting one client) is an allowable but tightly-scrutinized service model across most payers. Colorado Medicaid follows the same pattern: it does get approved, but only when specific clinical and safety criteria are documented and justified.

This guide covers how to request 2:1, what documentation is required, how ongoing justification works, and how Alpaca handles billing and data collection once it’s approved.

1. When 2:1 Staffing Is Appropriate

2:1 is not a convenience staffing model. It must be clinically necessary to maintain safety, deliver medically necessary treatment, or ensure staff can implement programming without risk.

Common justifications that payers recognize:

  1. High-risk behaviors

    • Severe aggression toward self or others

    • Property destruction creating unsafe environments

    • Frequent, unpredictable elopement

    • High-intensity tantrums with risk of harm

  2. Safety-related environmental demands

    • Community sessions where a single BT cannot maintain safety

    • High-stimulus settings where elopement risk increases

    • Homes with dangerous physical layouts (busy streets, pools, open access, etc.)

  3. Clinical necessity for treatment integrity

    • Intensive BSP implementation requiring simultaneous roles (block-and-redirect, safety monitoring, environmental modification, proactive prompting)

    • Transitions between multiple environments (e.g., car-to-store-to-playground)

    • Adaptive skills training that requires lifting/physical guidance while the second BT maintains safety

  4. BCBA recommendation based on objective data

    • Graphs showing spikes in high-risk behaviors

    • Incident reports

    • ABC logs

    • Session note trends

    • FBA results

Payers expect that the clinical risk is real, present, and measurable.

2. How to Request 2:1 Before Services Begin

If 2:1 is needed from the start, the request must go into the initial assessment and be included in the initial treatment plan.

A complete 2:1 request includes:

Required Components

  • Clear identification that 2:1 staffing is being requested

  • Clinical rationale tied directly to FBA results

  • Objective data:

    • frequency/duration/latency of unsafe behaviors

    • past incident reports

    • documented environments that require two staff

  • Why 1:1 is insufficient

    • Explain the risk

    • Connect risk to treatment integrity and safety

  • Expected timeline

    • Whether 2:1 is temporary or ongoing

    • Criteria for fading back to 1:1

  • How 2:1 supports treatment progress

    • Increased safety

    • Ability to implement BSP

    • Ability to teach skills without interruption

Sample Justification Language

“Based on the FBA, Client demonstrates X episodes of aggression per hour, including hitting, kicking, and biting, requiring continuous two-person blocking and redirection to maintain safety and implement the Behavior Support Plan with fidelity. One staff member cannot simultaneously maintain safety and conduct instructional trials. Therefore, 2:1 staffing is medically necessary.”

3. Requesting 2:1 After Therapy Has Started

(“Post-start 2:1” or “Mid-authorization 2:1”)

Sometimes new safety needs appear once treatment begins. You can request 2:1 mid-authorization through an amendment if you submit:

What must be sent:

  • All past data on all programs (behavior reduction and skill acquisition)

  • Recent incident data (graphs, logs, session note excerpts)

  • Specific examples of unsafe episodes

  • Explanation of what changed (regression, puberty, environmental shift, new setting, etc.)

  • BCBA narrative connecting the data to the need for 2:1

  • Clear statement of why 1:1 is no longer safe or sufficient

What payers expect:

  • Data covering multiple sessions, not a one-off behavior

  • Objective clinical evidence

  • A plan to reassess 2:1 regularly

Tip

The strongest mid-authorization requests include 3 things:

  1. A line graph showing increased unsafe behaviors

  2. Two or more incident summaries

  3. A short BCBA narrative explaining what changed

Alpaca can upload these directly when we submit the updated authorization request.

4. What Happens After 2:1 Is Approved

Once the payer approves the request, Alpaca updates the authorization in the system.

Billing (Colorado Medicaid Example)

  • 2:1 uses two separate 97153 claims (not a special code)

  • Each BT bills their own units

  • Example: 2-hour session

    • BT A: 8 units of 97153

    • BT B: 8 units of 97153

    • Total billed: 16 units

Documentation Requirements

  • Each RBT/BT must sign their own session note

  • Notes must reflect:

    • Staffing ratio

    • Target behaviors observed

    • Treatment protocols used

    • Any safety procedures implemented

    • Transitions and setting events that required two staff

BCBA Supervision

  • Still billable under standard 97155

  • BCBA must be present with the client

  • 97156 remains prohibited in Colorado Medicaid

  • Duplicate 97155 data points may need to be cleaned up (system defaults zero data when behavior doesn’t occur)

5. Data Collection During 2:1 Sessions

When two BTs start or interact with data collection:

What will happen in the system

  • Multiple data points may populate because each BT will have a data collection started

  • The system defaults to "0" data points if there are no behavior reduction data collected

  • So, if one staff collects data (but another doesn't), the data-collecting staff member will have a data point and there will be a 0 point from the non-data-collecting staff

  • BTs must coordinate:

    • Who is collecting skill-acquisition data

    • Who is documenting behaviors

    • Who is responsible for BSP implementation vs proactive teaching

  • BCBAs may need to delete duplicate points or read the graph per day rather than per session

Best practice

Assign roles before the session:

  • BT #1: Primary data collector

  • BT #2: Safety, blocking, transitions, environment support

This prevents duplicate data, missing data, and inconsistent trends.

During 97155 observation, you might need to delete auto-generated duplicates when no behavior occurred.

6. Fading Out of 2:1

Most payers will expect:

  • A fade plan

  • Criteria for reducing back to 1:1

  • Data-based justification for continuing 2:1

Examples of fading criteria:

  • “No aggression for 10 consecutive sessions”

  • “Reduction of elopement to fewer than 1 episode per week”

  • “Client maintains safety during transitions across three settings”

If fading is not appropriate, document why — and include data.

7. Common Reasons Payers Deny 2:1 Requests

  • Insufficient objective data

  • Broad statements like “safety concerns” without examples

  • Goals that do not require two staff

  • Lack of evidence that 1:1 was insufficient

  • Failing to demonstrate medical necessity

  • No fade plan

A strong request avoids all of these.

8. Summary

2:1 is absolutely approvable, but it requires strong, data-based justification. The keys are:

  • Show the risk

  • Show why 1:1 can’t safely deliver care

  • Show data

  • Explain how 2:1 solves the problem

  • Document clearly and consistently

Once approved, Alpaca automatically handles:

  • Authorization updates

  • Billing setup

  • Correct unit structure