CPT 97113Physical Therapy

Aquatic therapy/exercises

CPT code 97113 covers aquatic therapy or therapeutic exercises performed in a pool or water environment, supervised by a qualified healthcare professional. This includes water-based exercises designed to improve strength, range of motion, balance, and functional mobility.

Showing rates for

National Average

Base Medicare rate

$36.55

This calculator gives a typical-case estimate using standard Medicare modifier rules. Actual payment depends on payer policies, documentation, code-specific CMS status indicators, and locality. Verify before billing.

RVU breakdown

Work RVU

0.48

PE RVU (NF)

0.64

MP RVU

0.01

Total RVU

1.13

Conversion factor: 32.3465 · Source: CMS MPFS RVU25A · Confidence: High

NCCI bundling edits

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Billing tips

Bill based on 15-minute increments using the 8-minute rule; document exact start and stop times for each aquatic therapy session
Impact: Proper time documentation supports appropriate unit billing; 8-22 minutes = 1 unit ($36.55), 23-37 minutes = 2 units ($73.10)
Document specific aquatic properties utilized (buoyancy for unweighting, resistance for strengthening, hydrostatic pressure for edema control) to differentiate from land-based exercise
Impact: Clear differentiation prevents downcoding to 97110 (therapeutic exercise); maintains full $36.55 reimbursement per unit
Verify facility has appropriate pool temperature documentation and safety equipment to meet payer aquatic therapy requirements
Impact: Lack of facility documentation can result in retroactive denials requiring full refund; some commercial payers require pre-certification for aquatic therapy
Do not bill 97113 for same time period as 97110, 97112, or other therapy codes unless services are clearly distinct and separately documented
Impact: Concurrent billing without proper documentation triggers bundling edits; potential loss of $36.55 per overlapping unit plus audit risk
Ensure plan of care specifically authorizes aquatic therapy and documents why water-based intervention is medically necessary over land-based alternatives
Impact: Medical necessity documentation prevents denials as 'not reasonable and necessary'; some payers limit 97113 to specific diagnoses or conditions
Track therapy threshold amounts carefully and append KX modifier when exceeding Medicare limits with supporting documentation

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Frequently asked questions

What is the Medicare reimbursement rate for CPT code 97113 in 2025?

The 2025 Medicare national average payment for CPT 97113 is $36.55 per 15-minute unit for both facility and non-facility settings. This rate is based on 1.13 total RVUs multiplied by the 2025 conversion factor of 32.3465. Actual reimbursement may vary based on geographic locality adjustments.

How many units of 97113 can I bill per session?

Bill 97113 units based on the 8-minute rule: 8-22 minutes = 1 unit, 23-37 minutes = 2 units, 38-52 minutes = 3 units, and so forth. There is no absolute maximum, but medical necessity must support the duration. Most payers expect 2-4 units per session as typical, with longer sessions requiring strong justification for medical necessity.

Can I bill 97113 and 97110 together on the same day?

Yes, but only if performed during distinctly separate time periods and both are medically necessary. You cannot bill both codes for the same minutes. Document exact start/stop times for each service. If aquatic therapy transitions to land-based exercise in the same session, ensure each modality has at least 8 minutes of direct intervention to bill separately. Consider modifier 59 if payer bundling edits apply.

What documentation proves medical necessity for aquatic therapy?

Medical necessity documentation should include: specific diagnosis requiring reduced weight-bearing or joint stress, failed or contraindicated land-based therapy, specific water properties needed (buoyancy for support, resistance for strengthening), patient limitations preventing land exercise (severe pain, balance deficits, obesity), and expected functional outcomes achievable only through aquatic intervention. Include physician order specifically for aquatic therapy.

Do I need prior authorization for CPT 97113?

Prior authorization requirements vary by payer. Medicare typically does not require prior authorization for 97113, but you must track therapy thresholds. Many Medicare Advantage plans and commercial insurers do require pre-certification for aquatic therapy due to specialized facility requirements. Always verify authorization requirements with the specific payer before initiating treatment to avoid denials.

Can a physical therapist assistant bill CPT 97113?

Yes, a licensed physical therapist assistant (PTA) can perform and bill aquatic therapy under appropriate PT supervision according to state practice acts. Use modifier CQ to indicate PTA services. Some states and payers have implemented reduced payment for PTA services. The supervising PT must establish the plan of care, and PTA must document services according to the same standards as PT.

What is the difference between 97113 and 97110 for billing purposes?

CPT 97113 is specifically for therapeutic exercise performed in an aquatic environment utilizing water's unique properties (buoyancy, resistance, hydrostatic pressure). CPT 97110 is land-based therapeutic exercise. The distinction is the setting and use of water as the therapeutic medium. Aquatic therapy (97113) typically requires specialized pool facilities and may have different coverage policies. Both are time-based codes billed per 15-minute unit at the same Medicare rate of $36.55.