How Workers' Comp Disability Ratings Work
A disability rating is a standardized measurement of the permanent impairment you have sustained as a result of a work-related injury or illness. This rating is central to the workers' compensation system because it determines the level of permanent disability benefits you receive and is the primary driver of settlement value.
The Rating Process
The disability rating process begins after you reach Maximum Medical Improvement (MMI). At that point, a physician conducts a comprehensive evaluation that includes:
- Review of your complete medical history and treatment records
- Physical examination with objective measurements (range of motion, strength testing, sensory evaluation)
- Diagnostic imaging review (X-rays, MRI, CT scans)
- Functional capacity evaluation in some cases
- Application of the AMA Guides or state-specific rating criteria to assign an impairment percentage
The physician then issues a written report documenting their findings and the assigned impairment rating. This report becomes the foundation for your permanent disability benefits calculation.
Who Performs the Rating?
Depending on your state, the disability rating may be performed by:
- Your treating physician: The doctor who has been treating your injury
- An Independent Medical Examiner (IME): A physician selected by the insurance company to provide an independent evaluation
- A Qualified Medical Evaluator (QME): In California, a physician certified by the DWC to perform evaluations for unrepresented workers
- An Agreed Medical Evaluator (AME): A physician agreed upon by both parties (common in California when the worker is represented by an attorney)
IME Warning
Be aware that an Independent Medical Examination (IME) arranged by the insurance company may not always be truly independent. IME physicians are paid by the insurer and may have an incentive to minimize your rating. You have the right to request your own evaluation, and if the ratings differ significantly, the dispute may need to be resolved through mediation or a hearing.
Understanding the AMA Guides
The AMA Guides to the Evaluation of Permanent Impairment is the standard reference used in most states for rating workers' comp disabilities. Understanding how the Guides work helps you evaluate whether your rating is fair and accurate.
Editions Used by State
Different states require different editions of the AMA Guides. The two most commonly used are:
| AMA Guides Edition | States Using This Edition | Key Characteristics |
|---|---|---|
| 5th Edition (2001) | California, Alaska, Connecticut, Hawaii, Idaho, Kansas, Kentucky, Louisiana, Maine, Mississippi, Missouri, New Hampshire, New Mexico, Oklahoma, Oregon, South Carolina, South Dakota, Tennessee, Utah, Vermont, Virginia, West Virginia | Range-of-motion based; DRE vs. ROM methods for spine; generally produces higher ratings |
| 6th Edition (2008) | Georgia, Illinois, Indiana, Montana, New York, North Carolina, Wisconsin, Wyoming | Diagnosis-based; uses functional history, physical exam, and clinical studies; generally produces lower ratings |
| Other / State-Specific | Florida (Florida Uniform Impairment Schedule), Colorado (3rd Edition revised), Minnesota (Permanent Partial Disability Schedule), Texas (varies by date of injury) | State-developed or older editions; may differ significantly from AMA Guides |
Whole Person vs. Scheduled Loss
The AMA Guides rates impairment in terms of whole-person impairment (WPI), which represents the percentage of total body function that has been lost. Some states also use a scheduled loss system for extremity injuries (arms, legs, hands, feet, fingers, toes, eyes, ears), where benefits are calculated based on a fixed number of weeks assigned to each body part rather than a percentage.
For example, in New York, the scheduled loss for a leg (at the hip) is 288 weeks, for an arm (at the shoulder) is 312 weeks, and for a thumb is 75 weeks. The worker receives their weekly disability benefit for the assigned number of weeks.
Typical Disability Ratings by Injury Type
Disability ratings vary based on the specific injury, its severity, the body part affected, and the method of treatment. The following table provides general ranges based on the AMA Guides 5th Edition.
| Injury Type | Typical WPI Range | Notes |
|---|---|---|
| Lumbar disc herniation (no surgery) | 5–15% | DRE Category II-III; depends on radiculopathy |
| Lumbar disc herniation (with surgery) | 10–25% | DRE Category III-IV; higher with fusion |
| Lumbar spinal fusion (single level) | 15–28% | DRE Category IV; ROM method may yield higher |
| Cervical disc herniation | 8–20% | Similar categories as lumbar; may be higher if myelopathy |
| Rotator cuff tear (surgical repair) | 5–18% | Based on loss of ROM and strength |
| Total shoulder replacement | 20–35% | Significant ROM loss plus surgical factors |
| Meniscus tear (arthroscopic) | 3–10% | Based on ROM loss and residual symptoms |
| Total knee replacement | 15–35% | Depends on ROM outcome and gait impairment |
| Carpal tunnel syndrome (one hand) | 3–10% | Based on sensory/motor deficits; higher if surgery failed |
| Finger amputation (index) | 7–12% | Fixed value per AMA Guides table |
| Hand amputation | 40–54% | Dominant vs. non-dominant hand |
| Traumatic brain injury (moderate) | 20–50% | Based on cognitive, emotional, and physical deficits |
| Traumatic brain injury (severe) | 50–95% | May approach 100% with severe cognitive impairment |
| PTSD / psychological injury | 5–35% | Based on GAF score and functional limitations |
| Hearing loss (both ears) | 5–35% | Based on audiometric testing; binaural formula |
| Vision loss (one eye, total) | 24% | Fixed value per AMA Guides |
| Below-knee amputation | 28–40% | Based on function with prosthesis |
| Above-knee amputation | 40–60% | Higher if bilateral |
| Paraplegia | 60–80% | Based on neurological level and function |
| Quadriplegia | 80–100% | Typically rated at or near 100% |
Combined Ratings for Multiple Injuries
When a work injury affects multiple body parts, the ratings are combined rather than simply added together. The AMA Guides uses a Combined Values Chart that accounts for the fact that additional impairments affect a progressively smaller portion of the remaining whole person. For example, a 20% impairment combined with a 15% impairment yields 32% (not 35%), because the second impairment applies to the remaining 80% of the whole person: 20% + (15% x 80%) = 32%.
How Different States Handle Disability Ratings
While the AMA Guides provides the medical foundation, states take different approaches to converting impairment ratings into disability benefits.
Impairment-Only States
Some states base permanent disability benefits solely on the medical impairment rating. The doctor's WPI percentage is used directly to calculate benefits. Examples include Florida (which uses its own Florida Uniform Impairment Schedule) and many states that follow the AMA Guides rating without additional adjustments.
Loss of Earning Capacity States
Other states adjust the medical impairment rating based on the worker's loss of earning capacity. This considers factors such as the worker's age, education, skills, work experience, and the availability of jobs the worker can perform with their restrictions. These states may produce higher disability ratings for workers whose injuries significantly limit their job options, even if the medical impairment is moderate.
California's Unique Approach
California uses its own Permanent Disability Rating Schedule (PDRS), which converts the WPI percentage from the AMA Guides 5th Edition into a California disability rating using adjustments for the worker's age, occupation (using occupation groups), and diminished future earning capacity. This process can result in a California disability rating that is significantly higher or lower than the raw WPI percentage.
Scheduled Loss States
Many states use a schedule of benefits for injuries to specific body parts (arms, legs, hands, feet, fingers, toes, eyes, ears). Under this system, each body part is assigned a fixed number of weeks of benefits. The worker's disability percentage for that body part is multiplied by the total weeks to determine the benefit duration. For example, if the schedule assigns 200 weeks for a leg and the worker has a 30% loss of use of the leg, they receive 60 weeks of benefits.
Related Calculators and Resources
Use our other free tools and guides to better understand your workers' compensation benefits:
Frequently Asked Questions
Answers to the most common questions about this topic.
A workers' comp disability rating (also called impairment rating or permanent disability rating) is a percentage that represents the degree of permanent physical or mental impairment resulting from a work-related injury. Ratings range from 0% (no permanent impairment) to 100% (total disability). The rating is determined by a physician after you reach Maximum Medical Improvement and directly affects your permanent disability benefits and settlement value.
Disability ratings are typically calculated using the AMA Guides to the Evaluation of Permanent Impairment (most states use the 5th or 6th edition). A physician evaluates your condition, measures range of motion, strength deficits, and functional limitations, then assigns a whole-person impairment percentage based on the AMA Guides tables. Some states then apply additional adjustments for age, occupation, and earning capacity to convert the medical impairment into a disability rating.
An impairment rating is a medical assessment of physical or functional loss, typically expressed as a whole-person percentage using the AMA Guides. A disability rating is a broader concept used in workers' comp that may include the impairment rating plus adjustments for non-medical factors such as age, occupation, education, and loss of earning capacity. In some states (like California), the impairment rating is converted into a disability rating using a formula. In other states, the impairment rating is used directly for benefits calculations.
Yes, you can dispute your disability rating through several mechanisms depending on your state. Common options include: requesting an Independent Medical Examination (IME) or Qualified Medical Evaluation (QME); obtaining a second opinion from another physician; filing a formal dispute with your state's workers' comp board; and presenting medical evidence from your treating physician that supports a higher rating. Having an attorney who specializes in workers' comp can significantly help with the dispute process.
Maximum Medical Improvement (MMI) is the point at which your treating physician determines that your condition has stabilized and is unlikely to improve substantially with further medical treatment. Reaching MMI does not mean you are fully recovered; it means your condition is as good as it is going to get with current medical treatment. MMI is a critical milestone because it triggers the permanent disability evaluation and rating process, and it is typically required before a case can settle.
Your disability rating is the single most important factor in determining your permanent disability benefits and settlement value. Higher ratings result in: more weeks of permanent disability benefits, higher weekly benefit rates in some states, greater estimated future medical costs, larger loss of earning capacity calculations, and ultimately a higher settlement value. For example, a 25% disability rating might produce a settlement of $40,000-$80,000, while a 50% rating could result in $100,000-$250,000 or more, depending on the state and other factors.
Body parts and conditions that typically receive the highest disability ratings include: spinal cord injuries (paraplegia 60-80%, quadriplegia 80-100%), traumatic brain injuries (30-100%), amputations (arm above elbow 60-70%, leg above knee 50-60%), total loss of vision (85-100%), severe burns covering large body surface area (40-80%), and complex regional pain syndrome (20-60%). Multiple body part injuries can result in combined ratings that exceed what any single injury would produce.
The AMA Guides to the Evaluation of Permanent Impairment is a medical reference book published by the American Medical Association that provides standardized criteria for evaluating and rating permanent physical impairment. Most states require or reference the AMA Guides for workers' comp disability evaluations. The most commonly used editions are the 5th Edition (2001) and 6th Edition (2008). The edition used varies by state. The Guides provide detailed tables and criteria for rating impairments of every body system including musculoskeletal, neurological, cardiovascular, respiratory, and more.