CPT Code for Aquatic Therapy: Coding, Billing Guidelines & Documentation Requirements

Aquatic therapy can give physical therapists another way to help patients improve mobility, strength, balance, coordination, and functional movement. The buoyancy and resistance of water can make certain exercises easier to perform while reducing stress on painful or compromised joints.

The utilization of treatment exclusively in a pool does not qualify the treatment as payable. The physical therapist supplies the appropriate aquatic therapy CPT code, documents the skilled treatment, justifies the medical necessity, and submits the correct number of timed units.

Numerous services for therapeutic aquatic exercise has this common code: CPT 97113. According to the CMS, aquatic therapy with therapeutic exercises, is a service that uses therapeutic exercises in a water setting, and is billed when the patient’s condition warrants skilled rehabilitative care.

In this guide, we will go over how to code aquatic therapy, what to include in the bill, how 97113 differs from the other PT codes, and how billing mistakes can cause denials or delay payments.

What Is the CPT Code for Aquatic Therapy?

CPT Code for Aquatic Therapy The main CPT Code used is 97113 – Aquatic Therapy with Therapeutic Exercises.

Aquatic Therapy CPT when this form of treatment is prescribed to improve the function of the body or to diagnose and treat it. For buoyancy, resistance, or other effects on therapy in the water to debride or enhance balance.

The bottom line is that your documentation must support that aquatic therapy was warranted and show what expert intervention occurred that was the therapist doing, in addition to the fact that the patient was in a pool.

When Is CPT 97113 Appropriate?

CPT 97113 can be billed when the use of aquatic exercise is used to treat a working loss from an injury, diagnosis, pain, weakness, or range of motion restriction or other condition.

Examples may include treatment directed toward:

• Reduced joint mobility
• Muscle weakness
• Balance deficits
• Mobility limitations
• Functional movement problems
• Pain that limits land-based exercise
• Recovery following injury or surgery
• Conditions where water-based exercise supports progression toward land-based activity

As per the CMS guidance document, Aquatic Therapy “may be considered a reasonable and necessary service when the beneficiary is unable to participate in a land-based exercise program. The documentation must substantiate the need for an aquatic environment as well as clinical experience.

How CPT 97113 Differs from Other Physical Therapy Codes

One very common mistake is that the exercise is chosen by the code number to describe the therapy, instead of the location, purpose and documentation of the exercise.

Aquatic Therapy with Therapeutic Exercises (Code CTP 97113) versus Aquatic Therapy Programs (Code 97113): Only use AQUATIC Therapy with Therapeutic Exercises Programs when a code of 97113 will be used on the claim. Other services are based on a different code and cannot replace.

CPT Code	General Service	Relevance to Aquatic Therapy
97113	Aquatic therapy with therapeutic exercises	Primary aquatic therapy code
97110	Therapeutic exercises	Generally used for qualifying therapeutic exercise outside the aquatic service
97112	Neuromuscular reeducation	May apply when the documented service focuses on neuromuscular training
97116	Gait training	May apply when qualifying gait training is performed
97140	Manual therapy	Used for qualifying manual therapy services
97530	Therapeutic activities	Used for qualifying functional therapeutic activities
97150	Group therapeutic procedures	Used when qualifying therapy is delivered in a group setting

The presence of water alone does not mean every activity should be reported as 97113. The code should match the actual skilled service and payer requirements. Accurate medical coding services can help ensure the reported CPT code reflects the documented treatment.

CPT 97113 Units and Timed Billing

Knowledge of units is relevant to billing aquatic therapy because the CPT 97113 code is a timed therapy procedure.

Calculate units using the rules of the appropriate payer, rather than simply pick a unit based on scheduled appointment length.

For example, if you submitted the timed-unit method for a qualified 30-minute aquatic therapy treatment by the therapist, your document that you submitted should be sufficient. The document should also support the amount of treatment time submitted.

The record should make it possible to understand:

• When treatment began
• When treatment ended
• Total treatment time
• Treatment activities performed
• Skilled interventions provided
• Patient response
• Functional purpose of the treatment

CMS therapy guidance offers an annual update for coding and billing requirements of therapy services, so check with payers for any rules that may have changed before submitting claims.

Why Treatment Time Matters

A common error is documenting only the exercises and not the time associated with the service.

Take note such as “performed aquatic exercises” by itself does not document the treatment done or support the units documented.

The stronger notes what intervention were done, how long, what was the response and the clinical intent.

Medical record and claimant correspondence can be avoided with good time keeping.

What Should Aquatic Therapy Documentation Include?

Medical necessity is the foundation for all rigorous aquatic therapy documentation.

The record should establish the need for skilled aquatic treatment versus participation in a general water exercise program.

A useful aquatic therapy note may include:

Patient-Specific Impairments

Record the problem that is being addressed. For example, strength loss, ROM loss, balance dysfunction, pain, weakness, or loss of movement.

Skilled Interventions

List the exercises and techniques completed in the session. Please do not state “swimming completed”.

Rather, simply explain what therapeutic activities were performed and how the therapist altered or advanced them according to the patient.

Reason for the Aquatic Environment

Describe the reasons which make water treatment an ideal choice for this patient.

For instance, buoyancy may enable the patient to move with a reduced weight-bearing load, while water resistance may be a suitable means of providing an appropriately graded challenge.

Functional Goals

Connect the treatment to the plan of care. Relate the treatment to the functional goals.

The record should reflect how aquatic therapy helps to enhance mobility, ambulation, transfers, balance, strength or any other activity.

Patient Response

Document how the patient responded to the intervention and whether modifications were necessary.

Progress Toward Goals

Follow-up aquatic therapy sessions should show ongoing skill need and demonstrate measurable improvement if indicated.

The guidance from CMS states documentation should reflect that the aquatic treatment is the skilled component of the treatment, not that repetitive exercises are being completed.

Medical Necessity for Aquatic Therapy

Medical necessity is one of the most important parts of a winning aquatic therapy claim.

The payer can also question the claim when the record does not address why the patient requires aquatic therapy or how the service could not have been provided in another type of rehabilitative therapy.

The occupational or physical therapist should connect this aquatic activity to the patient’s impairment.

For example, the documentation might indicate the patient’s suffering from pain or weakness and poor tolerance to land-based strengthening. The therapist might allow the patient to perform controlled motions through the use of water buoyancy, and build resistance as the patient’s tolerance develops.

This creates a clear clinical connection:

Impairment → Need for aquatic environment → Skilled intervention → Functional goal → Measurable response

That connection is much stronger than documenting the pool exercises alone.

Aquatic Therapy vs. General Water Exercise

Not all exercise done in a pool is skill aquatic therapy.

This is particularly critical when it comes to a review of CPT 97113 billing.

General fitness activities, recreation swimming, water aerobics and/or maintenance exercises are not considered physical therapy coverage just because the activities are performed within a treatment setting.

The policy states that CMS guidance clearly defines skilled aquatic therapy separately from water exercise, which would be for the purpose of fitness, flexibility, endurance, aerobic conditioning, weight reduction or maintenance of weight, which would not meet the coverage criteria.

The medical record should therefore show why the service requires the knowledge and skill of the treating professional.

Can Aquatic Therapy Be Billed With Other PT Codes?

A patient can be seen for more than one physical therapy service within the same episode of care. Do not report multiple codes just because the services were provided in one visit, though.

All services reported must adhere to the appropriate coding and payer guidelines.

For instance, a clinician may provide an aquatic exercise treatment when indicated as part of a plan of care, and then another separate therapy service at that same visit. The documentation must distinguish the services and show that each reported service was individually supported.

Related codes may include:

• 97110 for qualifying therapeutic exercises
• 97112 for qualifying neuromuscular reeducation
• 97116 for qualifying gait training
• 97140 for qualifying manual therapy
• 97530 for qualifying therapeutic activities

CMS guidance also addresses direct patient contact and group therapy considerations. Providers should review the current payer policy before reporting multiple therapy services on the same date.

Common Aquatic Therapy Billing Errors

However, even when the appropriate aquatic therapy CPT code is selected, claim issues can occur if documentation and/or billing isn’t done properly.

Billing 97113 Without Skilled Treatment

One of the most common mistakes is billing for aquatic therapy when the record only supports routine exercise.

There should be an indicator of good practice within this record, showing you have taken professional action and why the patient is in need of professional treatment.

Failing to Support the Water-Based Setting

The therapist should explain why aquatic treatment is appropriate for the patient.

Without this connection, the payer may question medical necessity.

Incorrect Units

Reporting more units than the documented treatment time supports can create a claim discrepancy.

Copying the Same Note for Every Visit

Repeated notes with the same exercises, same times, and same responses by patient may be confusing as to how much skill is being used.

The treatment notes should describe what the patient really did and how he or she responded.

Using the Wrong Related Code

Deciding to select a different therapy code is due to the activity being similar to a service described by the code. Select the code based on the service provided and the coding conventions.

Ignoring Payer-Specific Requirements

Coverage criteria, documentation and billing and modifiers may be different between Medicare, Medicaid, and commercial payers. Medicaid and commercial payers may require additional precertification documentation.

Correct coding does not equal billable coding.

How to Reduce Aquatic Therapy Claim Denials

A good billing workflow for physical therapy begins long before the claim hits the payer.

Start off the process with the right patient details and insurance verification. Confirm the patient’s period of active coverage, and determine whether authorization or other payer authorizations should be obtained.

Then double check your therapist’s documentation before the claim goes in. The diagnosis, treatment, units and documentation should all be consistent.

A useful pre-submission checklist includes:

• Verify patient demographics
• Confirm insurance eligibility
• Review authorization requirements
• Confirm the diagnosis supports the treatment
• Select the appropriate CPT code
• Verify treatment time
• Check reported units
• Review modifiers when applicable
• Confirm documentation supports medical necessity
• Submit the claim within payer deadlines

This approach can help identify errors before they become denials.

When Should a PT Practice Consider Outsourcing Aquatic Therapy Billing?

However, aquatic therapy may be one more level of complication because it has to deal with therapy coding, time-based services, documentation, payer requirements, filing and follow-up.

Before choosing an outsourced billing partner, practices should compare the scope of services, claim volume, coding requirements, denial management, and overall medical billing pricing structure.

If practices see higher patient volumes, the billing personnel can fall behind on the revenue cycle.

This is where aquatic therapy medical billing services or broader physical therapy billing services can provide operational support.

A specialized billing team can help with:

• Patient eligibility verification
• CPT and ICD-10 coding review
• Claim preparation
• Claim submission
• Rejection correction
• Denial management
• Payment posting
• A/R follow-up
• Payer follow-up
• Billing reports

If providers wish to reduce the burden of insurance billing, outsourcing physical therapy billing services will offer a well-organized process without the provider having to handle all of the billing activities.

Why Accurate Coding Matters for Aquatic Therapy Reimbursement

Correct coding does more than place a code on a claim. It connects the clinical service to the payer’s reimbursement process.

With matching CPT code, diagnosis, units, documentation, and payer, the claim has an indication of much better eligibility.

Paid is not synonymous with reimbursed. Never assume you will be paid simply because you billed it correctly. Payor policy, patient benefit, medical necessity, authorization, contract, and bill accuracy all influence whether you get paid.

This is why aquatic therapy reimbursement should be classified under the overall revenue cycle, not a separate coding area.

How Professional Billing Support Can Help Physical Therapy Practices

There is a common concern of physical therapy practices that on one hand they want to provide superior patient care and on the other hand they have to handle the paper work. Coding, claims submission, denials, ARs require large amount of staff time.

Let professional coding and billing services for physical therapy take these duties off your back.

Eligibility verification, coding, claim submission, payment posting, denial management, and A/R follow-up can all be part of professional medical billing services in Minnesota.

Services like eligibility verification, coding, claim submission, payment posting, denial management and A/R follow-up can all make up part of a detailed billing process. According to Minnesota Billing Services, these are all specific functions within the scope of medical billing and revenue cycle management services for practices.

A complete billing workflow can also include patient balance management and patient statements in medical billing after insurance payments and adjustments are posted.

Collaborating with a billing group that understands physical therapy for Minnesota practices can also help more easily determine documentation deficiencies, issues with payers and ongoing claim challenges.

Final Takeaway

The primary CPT code for aquatic therapy is 97113. But a good billing experience is more than just knowing the proper code.

Medically necessary treatment listed in chart; purpose for aquatic therapy; skilled treatment listed in chart; motivation for amount of treatment; and relationship of treatment to patient goals.

Report individual PT codes only when the referring codes meet the criteria of that code. Check payer policies for billing requirements as they can sometimes be different by carrier.

Practices that maintain coding and documentation consistency can have peace of mind that they are prepared to make clean claims and get paid.

For physical therapy practices that need help with coding, claim submission, denial follow-up, and revenue cycle management, medical billing services in Minnesota can provide ongoing billing support while allowing providers to focus on patient care.

Our expert aquatic therapy billing services and physical therapy billing services for practices that need assistance will handle your coding, claims, denials, your A/R, and all of your revenue cycle services so you can spend your time with patients.

Frequently Asked Questions:

What is the CPT code for aquatic therapy?

The primary CPT code for aquatic therapy with therapeutic exercises is 97113. It is used when a qualified provider performs medically necessary therapeutic exercise in a water environment.

Is CPT 97113 a timed code?

Yes. CPT 97113 is a timed physical therapy service, so providers should document the treatment time and report units according to the applicable payer’s billing rules.

What documentation is required for aquatic therapy billing?

The documentation must include the support of medical necessity and describe the patient’s impairments and skilled intervention, treatment duration, functional goal attainment, patient’s response, and progress. Describe why the patient’s treatment cannot be performed without being in an aquatic environment.

Can CPT 97113 be billed with other physical therapy codes?

Potentially, yes, when the additional services are separately appropriate and meet the applicable coding and payer requirements. The documentation should clearly distinguish the services and support each reported code.

How can physical therapy practices reduce aquatic therapy claim denials?

These solutions can also help to minimize billing issues by validating insurance, validating authorizations, choosing the right codes, billing for time and medical necessity, validating units, and auditing claims. Using professional physical therapy billing services can assist in tracking coding, claims, denials, and accounts receivables.