Time-based CPT codes are some of the most misunderstood—and most frequently denied—codes across PT, OT, SLP, and behavioral health. If the documentation, timing, or rules don’t match payer expectations, claims get denied or underpaid.

This guide breaks down exactly how time-based codes work, the 8-minute rule, documentation requirements, and the common mistakes providers make without realizing it.

1. What Are Time-Based CPT Codes?

Time-based CPT codes reimburse based on the amount of direct, face-to-face treatment time you deliver.

Examples:

• 97110 – Therapeutic Exercise

• 97112 – Neuromuscular Re-education

• 97530 – Therapeutic Activities

• 97140 – Manual Therapy

• 90837 – 60-min psychotherapy

When a CPT code is time-based, the payer only reimburses if the minutes meet the threshold and the note supports that the provider was actively engaged.

2. The 3 Types of Billing Rules for Timed Codes

A. CMS 8-Minute Rule (Most Common)

Medicare and many commercial insurers use this rule.

A single timed unit requires at least 8 minutes of service.

This rule applies to almost all PT/OT/SLP time-based codes.

B. AMA Rule (Sometimes Used by Commercial Payers)

The AMA rule does not follow the Medicare total-time logic.

Under AMA:

• Each CPT code must meet its own time requirement

• You cannot combine minutes across codes

Some payers follow this rule. Most PT/OT clinics get denials because they assume “everyone follows Medicare.”

C. Behavioral Health Time Requirements

Psychotherapy codes have fixed durations:

• 90832 — 30 minutes

• 90834 — 45 minutes

• 90837 — 60 minutes

They use a range, not the 8-minute rule.

Example:
90837 (60 minutes) typically must show 53–60 minutes of therapy time.

3. Time-Based Codes Across Specialties

A. Physical Therapy (PT)

Common time-based codes:

• 97110 — Therapeutic Exercise

• 97112 — Neuromuscular Re-education

• 97140 — Manual Therapy

• 97530 — Therapeutic Activities

• 97116 — Gait Training

PT is heavily audited because time-based documentation often lacks detail.

PT Documentation Must Include:

• Total treatment time

• Minutes per CPT code

• Skilled interventions

• Objective functional change

• Provider involvement (no unskilled care)

B. Occupational Therapy (OT)

Common OT time-based codes:

• 97530 — Therapeutic Activities

• 97535 — Self-Care/Home Mgmt Training

• 97110 — Therapeutic Exercise

• 97112 — Neuromuscular Re-education

Many OT claims get flagged because documentation focuses on “tasks,” not functional goals.

C. Speech-Language Pathology (SLP)

SLP has fewer time-based codes, but insurers still audit heavily.

Common SLP time-based codes:

• 92507 — Speech therapy (individual)

• 92526 — Swallowing therapy

SLP notes must show:

• Skilled intervention

• Treatment rationale

• Progress toward functional communication/swallowing goals

D. Behavioral Health (Psychotherapy)

Psychotherapy codes have fixed duration ranges:

• 90832 – 30 min

• 90834 – 45 min

• 90837 – 60 min

If your note shows:

• Too short = denial

• Too long = payer flags for audit

• Missing “time in/time out” = denial

Behavioral health payers are strict—they check time documentation every single time.

4. Total Time vs. Code-Specific Time

For PT/OT/SLP:

• Medicare allows combining minutes from multiple time-based codes to calculate units.

• But each code must still have its own minutes documented.

Example:

• 97110 = 15 min

• 97140 = 10 min
  Total timed minutes = 25 → 2 total units billable
  But you cannot give 2 units to one code if documentation doesn’t support it.

5. What Does NOT Count as Time-Based Treatment?

Minutes that do NOT count:

• Rest time

• Setup time

• Waiting time

• Unattended modalities (e-stim unattended)

• Administrative work

• Observing the patient only

• Non-skilled services

Payers deny when they see “fluff minutes.”

6. Common Mistakes That Cause Denials

1. Total minutes documented, but no minutes per CPT code

Instant denial.

2. Notes saying “worked on goals” without skilled detail

Not enough.

3. Illegal stacking of minutes

Example: counting the same 10 minutes for two codes.

4. Behavior health session notes missing time in/time out

90837 denials skyrocket because of this.

5. Giving 3 units of one code when you didn’t document enough time

Very common PT mistake.

6. Group sessions billed as individual therapy

Instant audit trigger.

7. How to Document Time-Based Codes Correctly

Every note should include:

1. Total session time

Example: “Total treatment time: 55 minutes.”

2. Minutes per CPT code

Example:

• 97110 – 20 minutes

• 97112 – 15 minutes

• 97530 – 20 minutes

3. Skilled services delivered

Avoid generic statements like “patient tolerated well.”

4. Measurable progress

Payers want numbers, not feelings.

5. Functional impact

Tie therapy to real-life tasks.

8. How to Avoid Denials on Time-Based Codes

✔ Follow the 8-minute rule correctly

Most errors happen here.

✔ Do not round up minutes

Rounding is audit-triggering.

✔ Match time with clinical complexity

If you bill 4 units but document mild complexity, it looks suspicious.

✔ Train providers on documentation formats

Most denials come from the provider, not the biller.

✔ Use modifiers properly (GP, GO, GN)

Missing therapy modifiers = automatic denial.

Final Takeaway

Time-based CPT codes look simple, but insurance companies audit them tightly. When you understand the rules—the 8-minute rule, documentation requirements, and payer expectations—you eliminate denials and protect reimbursement.

PT, OT, SLP, and behavioral health clinics can significantly increase clean claims simply by mastering time-based coding.