Aquatic Therapy vs. Aquatic Fitness: What’s the Difference?

Dec 8 / Aquatic Therapy University
Understand the difference between aquatic therapy and aquatic fitness — who provides each, how they’re regulated, and why the distinction matters for therapists, students, and manufacturers.

Why This Matters

The words aquatic therapy and aquatic fitness are often used interchangeably online — sometimes even by facilities that should know better. But to a regulator, payer, or licensing board, they’re not cousins. They’re from entirely different families. If you’re a therapist, a pool designer, or a manufacturer marketing to rehab centers, knowing the difference is the line between skilled care and splash class.

Aquatic Therapy: As Defined by CPT Code 97113

Aquatic therapy is a skilled, clinician-driven intervention that uses the properties of water — buoyancy, hydrostatic pressure, viscosity, and thermal dynamics — to improve a patient’s functional performance.

It’s performed under a therapy license (PT, PTA, OT, OTA) and requires clinical reasoning, assessment, and documentation that justify the need for water over land.

The Academy of Aquatic Physical Therapy (APTA) defines aquatic therapy as:
“The evidence-based and skilled practice of physical therapy in an aquatic environment by a licensed therapist, using water’s properties to improve function, strength, endurance, and quality of life.”
Key characteristics:
• Delivered one-on-one or in a small supervised group.
• Involves a plan of care with measurable goals.
• Uses CPT 97113 for U.S. billing.
• Requires therapist presence and clinical decision-making.

IMPORTANT: The term "aquatic therapy" can also refer to services provided by other allied health care providers such as recreational therapists or kinesiotherapists working within the VA system. The definition above is restricted to the term as it is defined by the American Medical Association, and billable under CPT code 97113.

Aquatic Fitness: Guided. Recreational. Non-Billable.

Aquatic fitness (or water exercise) refers to general exercise in water aimed at improving or maintaining health, often delivered in group settings and not tied to a medical diagnosis.

It can be led by certified fitness instructors or exercise professionals without therapy licensure.

While fitness-based aquatic programs (like Aqua Zumba®, deep-water aerobics, or arthritis-friendly pool classes) can be valuable, they are not reimbursable under CPT 97113 because they don’t meet the medical necessity or skilled service criteria.

The American College of Sports Medicine (ACSM) describes aquatic exercise as:
“A low-impact form of exercise that uses water’s resistance to improve cardiovascular fitness, strength, and flexibility.” (ACSM, 2022)

In short:
• Usually group-based (1 instructor: many participants).
• Focused on general wellness, not functional restoration.
• May follow a standardized class format.
• Not billed under therapy codes.

Why the Distinction Matters

For therapists and facilities, this difference determines:
• Billing legality: CPT 97113 cannot be used for unskilled group exercise.
• Liability: Calling a pool class “therapy” implies clinical oversight, documentation, and adherence to health privacy standards.
• Reputation: Manufacturers and educators using “therapy” incorrectly can attract compliance audits and dilute the legitimacy of aquatic rehab professionals.

Attorney Michael Cook of Liles Parker LLP, a firm specializing in healthcare compliance, notes that misclassifying fitness as therapy is a common trigger for payer investigations and recoupments (Liles Parker, 2022).

International Context

• United Kingdom: “Hydrotherapy” typically refers to physiotherapy-based aquatic treatment. “Aqua exercise” or “aqua fitness” describes general fitness classes. NHS physiotherapists distinguish both explicitly in documentation.

• Australia: The Australian Physiotherapy Association recognizes hydrotherapy as a clinical extension of physiotherapy, while aquatic exercise may be led by exercise physiologists under non-therapy billing models (APA, 2023).

• Canada: Provincial regulations treat aquatic physiotherapy as a modality within physiotherapy practice, not as a separate certification.

• United States: The line is legal and financial — if it’s skilled, it’s therapy; if it’s general, it’s fitness.

Quick Comparison Table

Feature Aquatic Therapy Aquatic Fitness
Provider Licensed PT, PTA, OT, OTA Certified fitness instructor
Billing Code CPT 97113 (U.S.) None (private pay)
Documentation Required Optional
Goal Functional recovery General fitness
Setting Rehab or medical facility Gym, community pool
Group Size One-on-one or small group Large group
Legal Oversight One-on-one or small group General safety certification

The Bottom Line

If a licensed clinician, who is permitted to bill under the CPT code 97113, is using the water to restore a patient’s function, it’s probably aquatic therapy.

If the goal is general wellness or exercise without individualized medical reasoning, it’s probably aquatic fitness.

The water might look the same — but legally, the billing codes, scope of practice, and risk exposure couldn’t be more different.

References

• Academy of Aquatic Physical Therapy. (2024). FAQ: Aquatic Physical Therapy Practice. https://aquaticpt.org/faq
• Centers for Medicare & Medicaid Services. (2023). Local Coverage Determination L34241: Aquatic Therapy.
• American College of Sports Medicine. (2022). Aquatic Exercise Guidelines.
• Liles Parker LLP. (2022). Enforcement Targeting Aquatic Therapy Providers and CPT 97113 Claims.
• Australian Physiotherapy Association. (2023). Hydrotherapy Practice Standards.