Aquatic Therapy | What is Aquatic Therapy? Who Can Bill for Aquatic Therapy under CPT 97113?

Many disciplines can perform aquatic interventions, but not all can bill them as aquatic therapy (CPT 97113). So what is CPT code 97113 and who can bill for services with it? In the eyes of the law and your payer, aquatic therapy is a skilled, goal-driven medical procedure and subject to the same scrutiny as any land-based intervention. The last five years have tightened the definitions, the audits, and the expectations. If you’re billing for aquatic therapy using CPT code 97113, here’s what sources define as aquatic therapy in the United States.

Working definition (U.S.A.):

Aquatic therapy (CPT code 97113) is a skilled, goal-directed therapeutic procedure, delivered 1:1 in a water/aquatic environment, to treat a patient’s diagnosed injury, illness, or medical condition, provided by or under the supervision of a licensed PT/OT professional* as allowed by law, and documented in a plan of care. CPT 97113 is defined as “therapeutic procedure, 1 or more areas, each 15 minutes; aquatic therapy with therapeutic exercises.” It is not recreational pool exercise or general aquatic fitness and is covered only when medical-necessity criteria in payer or government policy are met. 

*Note: Aquatic interventions can be legally performed by more professions than PT/OT. This definition is specifically for aquatic therapy services billed under the CPT code 97113 since the 97XXX section of CPT code is restricted to PT/OT providers. SLP providers, for example, are legally permitted to provide services within their scope of practice in an aquatic medium; however, they would not use the code 97113 to seek reimbursement. Kinesiotherapists, for another example, are legally permitted to provide aquatic therapy within their scope of practice within the USA VA system (under federal law), but they do not bill for services under the CPT code 97113. Many other professions (therapeutic recreation, athletic training, massage therapy, exercise physiology, and more) can use the water to provide services as defined by their respective scopes of practice.

1. There is no single federal statutory definition

Current practice acts define physical therapy and occupational therapy broadly but do not carve out a separate, freestanding profession called “aquatic therapy.” That means U.S. law is treating aquatic work as a mode of PT/OT, not its own license (ECPTOTE, 2023; Washington State Legislature, 2023). Aquatic Therapy University (2025) supports this: “There is no such thing as an aquatic therapist in the eyes of the government; each provider works within their own licensed scope.” Because of that, the operative “legal” language you actually have to follow comes from:

• CPT/AMA coding (to tell you what you’re billing),

• Medicare/MAC LCDs and coding articles, and

• State Medicaid and commercial medical-necessity policies 
  (Aetna, 2023; Centers for Medicare & Medicaid Services, 2024)

2. CPT / AMA — the anchor

According to Aquatic Therapy University (2025), the 97113 code was introduced in 1995 to distinguish aquatic therapy as a procedure, not a modality, and should not be used for aquatic modalities like contrast baths or whirlpool. CPT 97113 says: “Therapeutic procedure, 1 or more areas, each 15 minutes; aquatic therapy with therapeutic exercises.” That gives three legal elements:
(a) it’s a therapeutic procedure (skilled),
(b) it must be in the water, and
(c) it must include therapeutic exercises (SpryPT, 2025; AAPC, 2024).

Supposition supported: “Aquatic therapy is skilled.”
The American Medical Association (CPT) places it in the Physical Medicine & Rehabilitation section, requiring therapist skill and one-on-one contact (AAPC, 2024).

3. Medicare / MAC LCDs

LCDs for outpatient PT/OT say aquatic therapy is covered only when the patient’s condition requires the unique properties of water and when skilled therapist involvement is needed (Centers for Medicare & Medicaid Services, 2024). Aquatic Therapy University (2025) states: All interventions should relate directly to an established list of problems and should have the patient’s specific and documented goals and functional outcomes as the driving force behind them.

Supposition supported: “It must be medically necessary and documented.”
Medicare LCD L34428 and its companion article make medical necessity, goals, and progress notes a condition of payment (CMS, 2024).

4. State Medicaid / state-level coverage 

Florida Medicaid’s 1/1/2025 PT fee schedule lists 97113 – Physical Therapy Treatment Visit – Aquatic Therapy right alongside land-based codes, confirming state recognition only when delivered under PT scope (Florida Health Care Admin, 2025). The 2024–2025 AmeriHealth/Keystone and Sunshine/Florida managed-care policies further specify coverage only for diagnosed impairments affecting ROM, strength, or mobility (AmeriHealth, 2024; Keystone First, 2024).

Supposition supported:  “It must treat a diagnosed condition.”
Every one of those policies ties coverage to an ICD-10-level diagnosis and a therapist-supervised plan of care (Keystone First, 2024).

5. Health & public-pool codes

The 2023 CDC Model Aquatic Health Code defines a “therapy pool” as a pool “used exclusively for aquatic therapy, physical therapy, or rehabilitation to treat a diagnosed injury, illness, or medical condition, wherein the therapy is provided under the direct supervision of appropriately licensed staff.” (CDC, 2023)

Supposition supported: “It happens in a designated aquatic environment and under licensed supervision.”
MAHC § 4.12.1 parallels CMS and state law requirements.

6. Current medical literature (2021–2025) backs that this is therapy, not recreation

Recent evidence identifies aquatic therapy as a clinical, diagnosis-driven intervention:

• JAMA Network Open (2022) — Aquatic exercise improved chronic low-back-pain outcomes vs. land PT.

• BioMed Central (2023–2025) — Non-inferiority or superiority shown for Parkinson’s disease, osteoarthritis, and ankle rehab.

Supposition supported: Medical literature in the last five years uses ‘aquatic therapy’ as a clinical, skilled, diagnosis-driven intervention. (JAMA Network, 2022; BioMed Central, 2025)

7. Distinguishing Features of Aquatic Therapy

Aquatic therapy:

• Is not a modality — Kaiser (2025) distinguishes hydrotherapy from skilled aquatic therapy. Aquatic Therapy University (2025) likewise states: “There are many technical and practical distinctions between hydrotherapy, the modality, and aquatic therapy, the procedure.”

• Must be performed 1:1 — TRICARE (2024) disallows group exercise as a covered therapy; Aquatic Therapy University (2025) confirms 97113 is a 1:1 code and that 97150 must be used for group sessions

• Requires a qualified provider — The Liles Parker (2022) compliance alert cites DOJ audits targeting facilities billing 97113 “for recreational or unskilled aquatic activity,” concluding: “Only therapy requiring the specialized knowledge and constant attendance of a licensed therapist qualifies.”

8. So what’s the best short-cut definition?

“Aquatic therapy (as reimbursable under CPT 97113) is a skilled, one-on-one therapeutic procedure performed by or under the supervision of a licensed PT/OT provider in a therapy pool or comparable aquatic environment, using the hydrodynamic properties of water to achieve goals in an established plan of care for a diagnosed condition.” 


References

American Medical Association. (2025). CPT 2025: Current procedural terminology (Standard ed.). Chicago, IL: American Medical Association.

Salzman, A. (2025). Billing & practice issues in aquatic therapy: A guide for the rehabilitation provider. Kingston, TN: Aquatic Therapy University.

Centers for Disease Control and Prevention. (2023). Model Aquatic Health Code (4th ed.). Atlanta, GA: U.S. Department of Health and Human Services.

Centers for Medicare & Medicaid Services. (2024). Outpatient therapy services: Coverage and documentation guidance. Baltimore, MD: Centers for Medicare & Medicaid Services.

Florida Agency for Health Care Administration. (2025). Medicaid therapy services fee schedule. Tallahassee, FL: Florida Agency for Health Care Administration.

Li, F., Harmer, P., Fitzgerald, K., Eckstrom, E., Akers, L., Chou, L.-S., ... & Song, R. (2022). Therapeutic aquatic exercise for chronic low back pain: A randomized clinical trial. JAMA Network Open, 5(8), e2225971. https://doi.org/10.1001/jamanetworkopen.2022.25971

Kaiser Permanente Medical Policy Department. (2025). Medical coverage policy: Aquatic therapy (CPT 97113). Oakland, CA: Kaiser Permanente.

Keystone First Clinical Policy Committee. (2024). Physical and occupational therapy medical necessity guidelines. Philadelphia, PA: Keystone First.

Liles, M. J., & Parker, D. J. (2022). Enforcement targeting aquatic therapy providers and CPT code 97113 claims. Washington, DC: Liles Parker PLLC. https://www.lilesparker.com/2022/10/05/enforcement-targeting-aquatic-therapy-providers-and-cpt-code-97113-claims/

Spry Physical Therapy. (2025). CPT 97113 – Aquatic therapy with therapeutic exercises. Retrieved from https://www.sprypt.com

Defense Health Agency, TRICARE Policy and Benefits Division. (2024). Rehabilitative services: Physical and occupational therapy policy manual. Falls Church, VA: U.S. Department of Defense.

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