Psychological Whole Person Impairment in California: How a GAF Score Becomes a Rating
Short answer: in California workers' compensation, a psychological injury is not rated with the body-system chapters of the AMA Guides. The evaluator assigns a Global Assessment of Functioning (GAF) score between 1 and 100, and the 2005 Permanent Disability Rating Schedule converts that score to whole person impairment with a fixed table. A GAF of 70 or higher is 0% WPI. A GAF of 60 is 15% WPI. A GAF of 50 is 30% WPI. Before the rating matters, the claim has to clear the compensability thresholds in Labor Code 3208.3, and for injuries on or after January 1, 2013, Labor Code 4660.1(c) bars most psychiatric ratings that arise as a consequence of a physical injury.
Session 3 of Perry J. Carpenter, DC, QME's report writing course uses psychiatric evaluation as the example of a specialty where the AMA Guides are not the rating protocol. It is a good example, because almost everything about it runs differently from an orthopedic case: the instrument, the legal thresholds, the apportionment fights, and the fee.
Why the AMA Guides do not rate psychiatric impairment
Chapter 14 of the AMA Guides, Fifth Edition, covers mental and behavioral disorders. It describes classes of impairment. It does not assign percentages to them. The authors said, in effect, that the science did not support putting a number on psychiatric impairment the way it can for a lost finger or a fused spine.
That left California with a problem when it adopted the Guides in 2005, because the rating formula needs a whole person impairment number to start from. The Division of Workers' Compensation solved it in the rating schedule itself. Section 1, subsection 4 of the 2005 schedule says psychiatric impairment "shall be evaluated by the physician using the Global Assessment of Function (GAF) scale," and the resulting score "shall then be converted to a whole person impairment rating using the GAF conversion table." The impairment number for the rating string is 14.01.00.00.
So the Guides are still the framework, in that the schedule cites page 2 for the definition of maximal medical improvement and Chapter 14 is what the physician is diagnosing within. The number itself comes from a scale that the Guides never used.
What the GAF scale measures
The GAF comes from Axis V of the DSM-IV-TR. It asks the evaluator to place the person's "psychological, social, and occupational functioning on a hypothetical continuum of mental health-illness," and to do it without counting "impairment in functioning due to physical (or environmental) limitations." That last clause matters in a comp case. A worker who cannot return to construction because of a fused lumbar spine is not, on that basis, psychiatrically impaired. The GAF looks at the depression, the anxiety, the panic, the sleep, the concentration, and what those do to the person's life.
The scale runs in ten-point bands. Each band describes a level of symptom severity and a level of functioning, joined by "or." The schedule reproduces the bands in full. Paraphrased:
| GAF band | What it describes |
|---|---|
| 91 to 100 | Superior functioning, no symptoms |
| 81 to 90 | Absent or minimal symptoms, good functioning in all areas |
| 71 to 80 | Transient, expectable reactions to stressors; no more than slight impairment |
| 61 to 70 | Some mild symptoms, or some difficulty in social or occupational functioning, but generally functioning pretty well |
| 51 to 60 | Moderate symptoms, or moderate difficulty in social or occupational functioning |
| 41 to 50 | Serious symptoms, or any serious impairment in social or occupational functioning |
| 31 to 40 | Some impairment in reality testing or communication, or major impairment in several areas |
| 21 to 30 | Behavior considerably influenced by delusions or hallucinations, or inability to function in almost all areas |
| 11 to 20 | Some danger of hurting self or others |
| 1 to 10 | Persistent danger of severely hurting self or others |
The schedule also gives a four-step method. Start at the top. At each band, ask whether either the symptom severity or the level of functioning is worse than the band describes. Keep moving down until you reach the band that fits, using whichever of the two is worse. Check the next band down to confirm it is too severe on both counts. Then pick the specific number within the ten-point band based on whether the person sits at the higher or lower end.
A word about the DSM. The DSM-5, published in 2013, dropped the GAF entirely. California did not. The 2005 schedule still governs, the GAF scale is printed inside it, and psychiatric QMEs go on assigning GAF scores because that is what the rating formula consumes. Labor Code 3208.3 separately requires the diagnosis itself to use the DSM or another nationally accepted psychiatric diagnostic manual, so the diagnosis comes from a current manual and the functional score comes from a retired one. Awkward, but that is the current law.
The GAF-to-WPI conversion table
Here is the conversion, from the schedule. The cutoff is sharp: 70 and above is zero.
| GAF | WPI | GAF | WPI | GAF | WPI |
|---|---|---|---|---|---|
| 70 and above | 0 | 60 | 15 | 50 | 30 |
| 69 | 2 | 59 | 17 | 49 | 32 |
| 68 | 3 | 58 | 18 | 48 | 34 |
| 67 | 5 | 57 | 20 | 47 | 36 |
| 66 | 6 | 56 | 21 | 46 | 38 |
| 65 | 8 | 55 | 23 | 45 | 40 |
| 64 | 9 | 54 | 24 | 44 | 42 |
| 63 | 11 | 53 | 26 | 43 | 44 |
| 62 | 12 | 52 | 27 | 42 | 46 |
| 61 | 14 | 51 | 29 | 41 | 48 |
Below 41 the table keeps climbing: a GAF of 40 is 51% WPI, 35 is 61%, 30 is 70%, and a GAF of 1 is 90%. Scores in that range describe people who are hospitalized or close to it, and they are rare in comp practice.
Notice what the table does to a one-point disagreement. A GAF of 70 is nothing. A GAF of 69 is 2% WPI, which after adjustment produces a permanent disability award. A GAF of 60 versus 59 is the difference between 15% and 17%. Every point is worth money, and everyone involved knows it, which is why psychiatric depositions spend so much time on why the evaluator chose 58 rather than 62.
From WPI to a permanent disability percentage
The WPI is the start of the rating string, not the end. For a psychiatric impairment the string is 14.01.00.00, then the WPI, then the adjustments.
For injuries on or after January 1, 2013, Labor Code 4660.1(b) applies a flat 1.4 multiplier to every WPI in place of the old future earning capacity ranks. A GAF of 60 gives 15% WPI, which becomes 21 after the multiplier. For injuries before 2013 the schedule assigned psychiatric impairment a future earning capacity rank of 8, the highest, which was also a 1.40 factor, so the arithmetic happens to come out the same. The rating is then adjusted for occupation and for age at the time of injury, and the result is the permanent disability percentage that maps to weeks of benefits.
A psychiatric rating with the same WPI as an orthopedic rating will usually be worth more after adjustment, because the psychiatric variant is high for most occupational groups. And none of this arithmetic is the evaluator's job. The evaluator's job is the GAF score and the reasoning behind it. The Disability Evaluation Unit runs the string.
The thresholds that come before the rating
A psychiatric QME spends a large share of the report on questions that an orthopedic QME never faces, because Labor Code 3208.3 makes psychiatric injuries harder to establish than physical ones. The rating is irrelevant unless the claim clears these.
A DSM diagnosis that causes disability or a need for treatment. The statute defines a compensable psychiatric injury as "a mental disorder which causes disability or need for medical treatment," diagnosed using DSM terminology and criteria. Stress without a diagnosable disorder is not an injury.
Predominant cause. The employee must show that "actual events of employment were predominant as to all causes combined" of the psychiatric injury. Predominant is read as more than 50%. The evaluator has to identify every cause, industrial and not, and say whether the work events outweigh all the rest put together. Non-industrial causes include prior psychiatric history, family stressors, substance use, financial problems, and anything else that contributed.
The violent act exception. Where the injury results from being a victim of a violent act or direct exposure to a significant violent act, the standard drops to "a substantial cause," which the statute defines as "at least 35 to 40 percent of the causation from all sources combined."
Six months of employment. No compensation for a psychiatric injury unless the employee worked for that employer at least six months, which need not be continuous, unless the injury "is caused by a sudden and extraordinary employment condition." A robbery is sudden and extraordinary. Routine job stress in the fifth month is not.
Good faith personnel actions. No compensation if the injury "was substantially caused by a lawful, nondiscriminatory, good faith personnel action." The evaluator will be asked to apportion causation between a demotion or a performance review, which is a personnel action, and, for example, harassment, which is not. Whether the action was lawful and in good faith is for the judge. What percentage of the causation it carries is for the physician.
Post-termination claims. Psychiatric claims filed after notice of termination or layoff are barred unless one of the statutory exceptions applies. The general post-termination rule for all injuries is covered in the post on Labor Code 3600(a)(10); 3208.3 has its own version with its own exceptions.
The report has to walk through each of these. A psychiatric report that jumps to a GAF score without addressing predominant cause and the six-month rule has answered the question nobody asked yet.
The 2013 bar on compensable consequence ratings
Most psychiatric claims in comp are not stand-alone. They are compensable consequences: a worker hurts a shoulder, cannot work, cannot sleep, and becomes depressed. Before 2013 the depression was rated and added to the shoulder.
Labor Code 4660.1(c), enacted in Senate Bill 863, ended that for injuries on or after January 1, 2013. Its text: "the impairment ratings for sleep dysfunction, sexual dysfunction, or psychiatric disorder, or any combination thereof, arising out of a compensable physical injury shall not increase." Treatment is still available. The statute says so expressly. What the worker cannot get is permanent disability money for the psychiatric consequence of a physical injury.
There are two exceptions. The rating may increase where the psychiatric injury resulted from:
- being a victim of a violent act or direct exposure to a significant violent act, as defined in 3208.3, or
- "a catastrophic injury, including, but not limited to, loss of a limb, paralysis, severe burn, or severe head injury."
"Catastrophic" is where the litigation lives. The Appeals Board addressed it en banc in Wilson v. State of California Cal Fire (2019), holding that the question turns on the nature of the physical injury rather than its mechanism, and listing factors: the intensity and seriousness of treatment, the ultimate outcome once the physical injury is permanent and stationary, the severity of the impact on activities of daily living, whether the injury is incurable or progressive, and whether it is closely analogous to the listed examples. A psychiatric QME evaluating a post-2013 compensable consequence claim should expect a cover letter asking for an opinion on those factors.
Note what the bar does not touch. A direct psychiatric injury, where the work events themselves caused the disorder, is rated normally. And the 4660.1(c) bar does not change the 3208.3 analysis; a compensable consequence claim still has to be a compensable injury for treatment purposes, which means the predominant cause test still applies to it.
Apportionment in a psychiatric report
Apportionment of psychiatric permanent disability runs under the same Labor Code 4663 and 4664 rules as any other body part, which is covered separately. Two features make it harder in practice.
The first is the difference between causation of injury and causation of disability. The 3208.3 predominant cause analysis is about what caused the injury. Apportionment is about what caused the permanent disability. They are separate questions with separate percentages, and a report that reuses the causation-of-injury percentages as the apportionment percentages has confused the two. A worker whose depression was 60% caused by work events can still have permanent disability that is 40% apportionable to a pre-existing dysthymia, or 10%, or 70%, depending on what the evaluator finds actually drives the current level of functioning.
The second is that psychiatric history is usually documented somewhere other than the psychiatric records. Prior counseling shows up in primary care notes. A past prescription for an SSRI shows up in a pharmacy printout inside a 900-page production. A divorce, a bankruptcy, or a death in the family shows up in a deposition transcript. A psychiatric evaluator who did not see those pages cannot apportion to them, and the resulting opinion is exactly the kind of speculation that fails the substantial medical evidence test.
What the report needs to say
Pulling the threads together, a defensible psychiatric medical-legal report in California does the following, in roughly this order:
- States the DSM diagnosis and the criteria met, from the interview, testing, and records.
- Addresses each 3208.3 threshold that applies: predominant cause with the percentages, the six-month rule, personnel actions, and post-termination status if raised.
- Assigns a GAF score, shows the four-step reasoning, and explains the specific number within the band.
- Converts the score to WPI using the schedule's table and states the impairment number 14.01.00.00.
- For post-2013 compensable consequence claims, addresses 4660.1(c) and, if the parties ask, the Wilson factors on catastrophic injury.
- Apportions the permanent disability under 4663 and 4664, with the reasoning, separately from the causation-of-injury analysis.
- States whether the condition is permanent and stationary, what future treatment is reasonably required, and what the work restrictions are.
Psychological testing is not required by statute but is nearly universal in these reports, partly because it gives the GAF score something to stand on and partly because validity scales address the credibility questions that every psychiatric claim raises.
For fee purposes, a psychiatrist or psychologist bills the evaluation with modifier -96, which doubles the base medical-legal fee under 8 CCR 9795. The doubled fee reflects the time these evaluations take. A psychiatric interview alone commonly runs several hours, and the record review behind a compensable consequence claim covers the entire physical injury file as well as the psychiatric history.
That record review is where Lexamed fits. A psychiatric evaluator working a consequence claim needs the prior mental health references, the medication history, and the life events pulled out of a production that was assembled for an orthopedic case. Lexamed builds a page-cited chronology from the full production and flags the psychiatric history within it, so the 3208.3 causation analysis and the 4663 apportionment rest on pages the physician has seen rather than on what the examinee remembered to mention.
Frequently asked questions
What is psychological whole person impairment? In California workers' compensation, it is the whole person impairment percentage assigned to a psychiatric injury. Because the AMA Guides do not assign percentages to mental disorders, the 2005 rating schedule requires the evaluator to assign a Global Assessment of Functioning score and convert it to WPI with a fixed table.
What GAF score gives 0% whole person impairment? Any GAF score of 70 or higher converts to 0% WPI under the schedule's table. A GAF of 69 converts to 2%.
How does a GAF score convert to WPI? By table. Selected values: GAF 65 is 8% WPI, GAF 60 is 15%, GAF 55 is 23%, GAF 50 is 30%, GAF 45 is 40%, GAF 40 is 51%. The full table appears in Section 1, subsection 4 of the 2005 Permanent Disability Rating Schedule.
Is the GAF still used if the DSM-5 removed it? Yes, in California workers' compensation. The 2005 rating schedule still governs, it reproduces the GAF scale in full, and psychiatric evaluators assign GAF scores because that is what the rating formula requires. The diagnosis itself is made under a current diagnostic manual.
What is the predominant cause standard for a psychiatric injury? Under Labor Code 3208.3, actual events of employment must be predominant as to all causes combined, meaning more than 50% of the causation. Where the injury results from a violent act, the standard drops to a substantial cause, defined as at least 35 to 40 percent.
Can a worker get a psychiatric rating for depression caused by a physical injury? For injuries on or after January 1, 2013, generally no. Labor Code 4660.1(c) bars increases in permanent disability for psychiatric disorders arising out of a compensable physical injury, unless the psychiatric injury resulted from a violent act or from a catastrophic injury such as loss of a limb, paralysis, severe burn, or severe head injury. Treatment for the psychiatric condition remains available.
Do you need six months on the job to claim a psychiatric injury? Yes, with one exception. Labor Code 3208.3 requires at least six months of employment with that employer, not necessarily continuous, unless the psychiatric injury was caused by a sudden and extraordinary employment condition.
How is a psychiatric medical-legal evaluation billed? Under 8 CCR 9795, a psychiatrist or psychologist appends modifier -96 to the medical-legal code, which multiplies the base fee by 2.0.