ICD-10 Codes for Physical Therapy: A Quick-Reference Guide

August 11, 2026

TL;DR

This guide lists commonly used PT ICD-10 codes for spine, joint, weakness, gait, balance, fall risk, injury, and postsurgical conditions.
Physical therapists, billing staff, and clinic directors can use the tables during documentation and claim review.
Laterality matters. Choose right, left, or bilateral codes when the diagnosis supports them rather than defaulting to unspecified codes.
Injury codes often require a seventh character. Initial and subsequent encounter designations reflect the treatment phase, not simply whether the visit is the patient’s first or a later visit.
The documented diagnosis should match the examination findings, functional limits, and plan of care.

Quick-reference table: the ICD-10 codes PTs use most

Use the most specific billable ICD-10-CM code supported by the evaluation, referring diagnosis, and current documentation. Codes ending in a hyphen below are category stems that require additional characters.

Spine and back

Condition	ICD-10-CM code	Common use case
Low back pain	M54.50	Low back pain without a more specific established diagnosis
Cervicalgia	M54.2	Neck pain without documented radiculopathy
Thoracic spine pain	M54.6	Pain localized to the thoracic region
Lumbar radiculopathy	M54.16	Lumbar symptoms with documented nerve-root involvement
Cervical radiculopathy	M54.12	Cervical symptoms with documented nerve-root involvement

Joint and extremity pain

Condition	ICD-10-CM code	Common use case
Shoulder pain	M25.511 right, M25.512 left	Pain without a more specific shoulder diagnosis
Hip pain	M25.551 right, M25.552 left	Hip pain without an established pathology
Knee pain	M25.561 right, M25.562 left	Knee pain without a more specific diagnosis
Ankle and foot joint pain	M25.571 right, M25.572 left	Pain involving the ankle or foot joints
Wrist pain	M25.531 right, M25.532 left	Wrist pain without a more specific diagnosis
Unilateral primary knee osteoarthritis	M17.11 right, M17.12 left	Confirmed primary knee osteoarthritis

Weakness and deconditioning

Condition	ICD-10-CM code	Common use case
Generalized muscle weakness	M62.81	Documented generalized muscle weakness affecting function
Weakness	R53.1	Nonspecific weakness when no more precise diagnosis applies
Physical deconditioning	R53.81	Reduced functional capacity documented as deconditioning

Gait and balance

Condition	ICD-10-CM code	Common use case
Difficulty walking	R26.2	Walking limitation not classified elsewhere
Unsteadiness on feet	R26.81	Balance impairment during standing or walking
Other gait abnormality	R26.89	Gait dysfunction not covered by a more specific code
Repeated falls	R29.6	Current pattern of repeated falls
History of falling	Z91.81	Documented history of falling, commonly secondary

Post-surgical and post-injury status

Condition	ICD-10-CM code	Common use case
Orthopedic aftercare	Z47.89	Rehabilitation after completed orthopedic treatment
Aftercare following joint replacement	Z47.1	Rehabilitation after joint-replacement surgery
Presence of artificial knee joint	Z96.651 right, Z96.652 left	Status code accompanying knee-replacement aftercare
Presence of artificial hip joint	Z96.641 right, Z96.642 left	Status code accompanying hip-replacement aftercare
ACL sprain	S83.51-	Requires laterality and an encounter character
Ankle ligament sprain	S93.4-	Requires ligament detail, laterality, and an encounter character

Confirm code selection against the current ICD-10-CM release and payer rules before claim submission.

Spine and back conditions

Use the most specific spinal region and diagnosis supported by the established diagnosis, examination, and referral information. Common symptom codes include M54.50 for unspecified low back pain, M54.51 for vertebrogenic low back pain, M54.2 for cervicalgia, and M54.6 for pain in the thoracic spine. M54.59 covers other low back pain when the documented condition does not fit a more specific option.

Radiculopathy codes require documentation of nerve root involvement rather than localized or referred pain alone. Common examples include M54.12 for the cervical region, M54.14 for the thoracic region, M54.16 for the lumbar region, and M54.17 for the lumbosacral region. Your examination should connect the diagnosis to findings such as a dermatomal sensory change, myotomal weakness, altered reflexes, or a relevant neural tension response.

Generic pain codes remain appropriate when no more specific diagnosis has been established. Do not infer radiculopathy, disc disease, or vertebrogenic pain from the pain pattern alone. When imaging, referral documentation, or examination findings support a recognized condition, the claim should use the corresponding code rather than defaulting to unspecified back pain.

Code specificity helps the payer compare the diagnosis with the plan of care and requested services. An unspecified code can prompt an edit or documentation request when the chart clearly identifies the spinal region or condition. The evaluation, goals, and treatment record should use consistent terminology so the submitted diagnosis reflects the functional deficits addressed in physical therapy.

Joint and extremity pain

Laterality determines the complete ICD-10 code for most joint pain diagnoses. Common examples include M25.511 for right shoulder pain, M25.562 for left knee pain, M25.551 for right hip pain, M25.572 for left ankle and foot joint pain, and M25.531 for right wrist pain. The corresponding unspecified-side codes end in 9, such as M25.519 for unspecified shoulder pain.

Use right or left whenever the evaluation and plan of care identify a side. When both sides require treatment, most joint pain code families require separate right and left codes rather than one bilateral code. An unspecified code can conflict with a clearly side-specific chart and may prompt a payer query or denial.

Match the code to the documented condition rather than defaulting to pain. For example, M17.11 describes unilateral primary osteoarthritis of the right knee, while M25.561 describes right knee pain without identifying osteoarthritis as the cause. When the referring diagnosis or available clinical documentation establishes osteoarthritis, fracture, tendon disorder, or another specific condition, that diagnosis generally provides more information than a symptom code.

Pain and stiffness may support separate codes when the record evaluates both impairments and each one affects the plan of care. Avoid adding multiple symptom codes that describe the same problem without distinct documentation. Confirm the diagnosis, side, joint, and current code description before submitting the claim, since payer rules and code sets can change.

Weakness and deconditioning

The ICD-10 code for generalized muscle weakness is M62.81. Use it when the examination identifies reduced muscle performance across multiple regions rather than weakness isolated to one injured joint or limb. Objective findings may include manual muscle testing, dynamometry, repeated sit-to-stand performance, or reduced functional capacity.

R53.1 describes weakness as a general symptom, while R53.81 may apply to documented physical deconditioning under the broader description of other malaise. When a confirmed condition already explains the weakness, code that underlying diagnosis first when appropriate. You may add weakness as a secondary diagnosis if you assess it separately and it changes the plan of care.

Weakness codes require documentation that connects the impairment to skilled physical therapy. Record the measured deficit, the affected activity, and why the patient needs skilled assessment or progression. For example, lower-extremity weakness may limit transfers or stair negotiation and require graded strengthening with reassessment. Age alone does not establish medical necessity, so avoid describing weakness only as age-related decline without measurable impairment and functional effect.

Review M62.81, R53.1, and R53.81 against the referral, examination findings, payer rules, and current ICD-10 guidance before claim submission. Avoid carrying a generalized weakness code forward after the record supports a more specific diagnosis.

Gait and balance, including fall risk

R26 codes describe the functional gait impairment that physical therapy evaluates and treats. Common options include R26.2 for difficulty walking, not elsewhere classified, R26.81 for unsteadiness on feet, and R26.89 for other abnormalities of gait and mobility. R26.9 covers an unspecified gait abnormality, but a more specific code should be used when the evaluation supports one.

R29.6 applies when a patient has fallen recently and the cause of the fall is still being worked up. Z91.81 documents a history of falling when that history is relevant to preventing future falls, so it usually serves as a secondary diagnosis rather than the primary reason for skilled care. An external-cause code such as W19 does not describe future fall risk. It identifies an actual fall event and requires the applicable encounter character.

Patients who screen as high risk without a previous fall require careful coding. Some payers may accept Z91.89 for another specified personal risk factor, but payer rules and the current code set should guide selection. Documentation should name the findings behind the risk, such as unsteady gait, impaired transfers, reduced lower-extremity strength, or poor balance-test performance.

A gait or balance impairment often supports the primary diagnosis more directly than a risk-status code. For example, R26.81 may serve as the primary code when unsteadiness drives the plan of care, while Z91.81 records the patient's fall history as a secondary factor. Using a fall-risk code alone can leave the claim without a clear functional impairment or explanation of why skilled physical therapy is medically necessary.

Post-surgical and post-injury status codes

The seventh character on an injury code identifies the phase of care, not the number of visits. An initial encounter character, usually A, applies while the patient receives active treatment for the injury. A first physical therapy visit may already require a subsequent encounter character if routine healing and rehabilitation have begun.

A subsequent encounter character, usually D, applies during recovery after active treatment ends. Physical therapy for healing fractures, sprains, and other injuries commonly falls into this phase. Clinicians should confirm that the code stem, required placeholders, and seventh character create a complete billable code.

A sequela character, usually S, applies when a patient receives care for a residual problem after the acute injury has healed. For example, persistent weakness following a healed fracture may require the weakness code first and the fracture code with S second. Sequela coding does not describe routine recovery during the original healing period.

Post-surgical rehabilitation may use an orthopedic aftercare code such as Z47.1 after joint replacement or Z47.89 after other orthopedic surgery. A joint replacement case may also require a code identifying the replaced joint, such as a specific code from the Z96.6 category. By contrast, injury rehabilitation generally continues to use the injury code with the correct subsequent encounter character rather than a general aftercare Z-code.

Do not carry an initial encounter character through follow-up visits solely because the physical therapy plan of care remains open. The clinical phase changes when active injury treatment gives way to routine healing, rehabilitation, or care for a lasting residual. Documentation should identify the procedure or injury, current healing phase, affected side, and functional impairment so the diagnosis sequence supports the services billed. Payer instructions and official coding guidance should resolve cases where surgical aftercare, complications, and the original diagnosis overlap.

From diagnosis code to plan of care

Once you confirm the diagnosis codes, connect each coded impairment to measurable goals and prescribed activities. Physitrack’s HEP Builder helps you turn the home exercise program into a trackable part of the plan of care. You can select exercises, set dosage, and adjust the program as the patient progresses.

Physitrack serves as the exercise prescription layer alongside your existing EHR and billing systems, including supported Epic workflows. It does not assign ICD-10 codes, create SOAP notes, or replace the patient record.

During re-evaluation, adherence data can add context to your objective findings and clinical assessment. PhysiApp records exercise completion, sets and repetitions, and patient-reported pain and difficulty for each session. You can use those records to explain whether the patient followed the prescribed plan, how the patient responded, and why skilled progression or modification remains appropriate. The EHR should retain the diagnosis, plan of care, re-evaluation findings, and medical necessity documentation.

Ofte stillede spørgsmål

How do I choose the primary versus secondary diagnosis? The primary diagnosis should represent the condition chiefly responsible for skilled physical therapy. Physitrack does not select diagnosis codes because it supports exercise prescription rather than coding or billing. Secondary codes can document related impairments, comorbidities, or fall risk when they affect the plan of care.
How many ICD-10 codes can be billed on one claim? Payer rules and claim-form limits determine how many diagnosis codes you may report. Physitrack does not control claim submission or payer requirements. Include only diagnoses supported by the evaluation, documentation, and services billed.
Can unspecified ICD-10 codes cause a denial? An unspecified code can increase denial risk when the record supports a more specific code, such as right or left laterality. Physitrack operates alongside the EHR and billing system where clinicians record that detail. Specific coding helps the claim match the evaluation and plan of care.
How often should ICD-10 codes be reviewed during a plan of care? Clinicians should review codes at the evaluation, re-evaluation, recertification, and any meaningful change in diagnosis or functional status. Physitrack can carry the established plan into exercise delivery, but the EHR remains the coding record. Regular review prevents resolved, outdated, or unsupported diagnoses from remaining on later claims.

Kevin Kaminyar

Global vækstchef