CPT® Code 97110

Quick Reference: CPT 97110

• Definition: Therapeutic exercises to develop strength, endurance, range of motion, and flexibility.
• Billing Unit: 15 minutes (Time-Based). Follows the 8-Minute Rule (8 mins or more = 1 unit).
• Requirement: Direct, one-on-one patient contact. Group exercises must use code 97150.
• 2026 Medicare Threshold: The KX modifier threshold is now $2,480.
• Bundling: Commonly bundled with Manual Therapy (97140). Use Modifier 59 only if services are distinct (separate region or time).

Definition and Included Services

CPT code 97110 refers to therapeutic exercises provided to a patient, typically by a physical therapist, occupational therapist, or other qualified provider. The goal is to improve strength, endurance, range of motion (ROM), and flexibility.

The official code descriptor is: "Therapeutic procedure, one or more areas, each 15 minutes; therapeutic exercises to develop strength and endurance, range of motion and flexibility."

In practical terms, 97110 covers:

• Active, active-assisted, or passive exercises.
• Stretching routines for flexibility.
• Resistance training (weights, bands, machines) for strength.
• Endurance training (treadmill, bike) specifically for deconditioning.

Importantly, 97110 is a time-based code billed in 15-minute units. The therapist must provide at least 8 minutes of direct, one-on-one contact to bill a single unit. Group exercise sessions do not count for 97110.

Typical Clinical Indications and ICD-10 Codes

Therapeutic exercise is medically necessary when a patient has a specific loss of function that can be improved through exercise. Common indications include:

• Muscle Weakness/Atrophy: e.g., Generalized muscle weakness (M62.81) after immobilization.
• Limited Range of Motion: e.g., Stiffness of joint (M25.60) following surgery or injury.
• Post-Surgical Rehab: e.g., Rotator cuff repair aftercare (Z47.89) requiring strengthening.
• Chronic Pain Deconditioning: e.g., Low back pain (M54.5) requiring core stabilization.
• Balance Deficits: Difficulty walking (R26.2), often used alongside neuromuscular re-education (97112).

Documentation Requirements (Audit-Proofing)

To ensure reimbursement and survive audits (like TPE reviews), documentation must be specific:

• Evaluation: Must establish a baseline with objective measures (e.g., "Quad strength 3/5", "Knee flexion 90 degrees").
• Plan of Care (POC): Must include diagnosis, long-term goals, and frequency/duration (e.g., "3x/week for 6 weeks").
• Daily Treatment Notes:
  • Specifics: List the exercises (e.g., "3 sets of 10 leg presses at 50lbs").
  • Time: Document total timed minutes. (e.g., "25 mins therapeutic exercise").
  • Skilled Intervention: Document what the therapist did (e.g., "Provided verbal cues for lumbar alignment," "Adjusted resistance to prevent substitution").
• Progress Reports: Required every 10 visits (Medicare). Must show functional improvement (e.g., "Patient can now climb stairs reciprocally").

Medicare and Payer Coverage Rules (2026)

Medicare Part B

• KX Modifier Threshold (2026): The threshold for PT/SLP combined is $2,480. Once a patient's therapy costs exceed this amount in a calendar year, you must append the KX modifier to 97110 to attest that services remain medically necessary.
• Discipline Modifiers: All claims must include GP (Physical Therapy), GO (Occupational Therapy), or GN (Speech Therapy).
• Certification: The Plan of Care must be certified by a physician/NPP within 30 days of the initial visit.

Private Payers (Aetna, UHC, BCBS)

• Unit Limits: Many commercial payers (e.g., Aetna, UHC) limit daily reimbursement to a maximum of 4 units of timed therapy per visit, regardless of duration.
• Assistant Modifiers: As of 2025/2026, major payers like Aetna and Anthem require the CQ (PT Assistant) or CO (OT Assistant) modifiers, mirroring Medicare policy.

Time-Based Billing (The 8-Minute Rule)

Medicare and most federal payers use the 8-Minute Rule to calculate billable units for timed codes like 97110. You cannot bill for services lasting less than 8 minutes.

Warning: Only skilled time counts. If a patient is on a treadmill for 15 minutes unsupervised while the therapist charts or treats another patient, that time is not billable under 97110.

Comparing 97110 vs. 97530, 97112, 97140

Selecting the right code depends on the intent of the intervention:

Modifier Guide (59, GP, KX, CQ)

Modifiers are essential for bypassing NCCI edits and meeting payer rules.

• Modifier 59 (Distinct Procedural Service): Used to unbundle codes that are linked by NCCI edits. The most common pair is 97140 (Manual) and 97110 (Exercise). Rule: You can only use 59 if the services were performed in separate 15-minute intervals or on distinct anatomical regions.
• Modifier GP/GO: Always required to indicate the therapy plan of care.
• Modifier KX: Mandatory for claims over $2,480 (2026 threshold).
• Modifier CQ/CO: Used when a Physical Therapist Assistant (CQ) or Occupational Therapy Assistant (CO) provides at least 10% of the service.

flowchart TD
    A[Bill 97110?] --> B{Service ≥ 8 min\none-on-one?}
    B -- No --> C[Do NOT bill 97110]
    B -- Yes --> D{Also billing\n97140 same visit?}
    D -- No --> E[Bill 97110 units\n+ GP/GO modifier]
    D -- Yes --> F{Separate time block\nor distinct region?}
    F -- No --> G[Bundle: bill 97110 only]
    F -- Yes --> H[Bill 97110 + 97140-59]
    E --> I{Year-to-date\ntherapy > $2,480?}
    H --> I
    I -- No --> J[Submit claim]
    I -- Yes --> K[Add KX modifier\nthen submit]

Real-World Coding Scenarios

Scenario 1: The "Bundled" Session (Knee Rehab)

Service: Therapist spends 25 minutes on leg strengthening exercises (97110) and 15 minutes performing manual joint mobilization (97140) to the same knee.

Coding: 97110 (2 units) + 97140-59 (1 unit).

Reasoning: NCCI bundles 97140 into 97110. Modifier 59 is required on 97140 to indicate it was a distinct skilled service performed in a separate time block.

Scenario 2: Stroke Rehab (Balance vs Strength)

Service: 15 minutes of balance training on a wobble board + 15 minutes of leg press exercises.

Coding: 97112 (1 unit) + 97110 (1 unit).

Reasoning: No modifier needed. 97112 targets balance (neuro re-ed), while 97110 targets strength. They are distinct codes.

Scenario 3: Mixed Group and Individual

Service: Patient attends a 45-minute group circuit class, then receives 15 minutes of one-on-one shoulder stretching.

Coding: 97150 (1 unit) + 97110 (1 unit).

Reasoning: Group therapy (97150) is untimed (always 1 unit). The individual session meets the 8-minute rule for 1 unit of 97110. Documentation must clearly separate the two sessions.