If you’ve been injured on the job in California, there’s one moment in your workers’ comp case that can change everything: the moment your doctor decides you’ve reached maximum medical improvement (MMI) and assigns your Permanent Disability (PD) Rating.
That tiny percentage (10%, 15%, 22%) can determine your future medical care, your financial stability, and the true value of your case. Yet most injured workers have no idea how that number is calculated or how much power it really holds.
And you're not alone. Everyone feels lost the first time they hear terms like MMI, whole person impairment, or apportionment. The system isn’t designed to be easy, so here’s the clear, human explanation you deserve.
When Your Doctor Says You’ve “Stopped Improving”
Reaching MMI doesn’t mean you're healed. It simply means your doctor believes your condition won’t improve in any meaningful way over the next 12 months, even if you keep getting treatment.
This is the moment the insurance company has been waiting for, because now your disability gets a value attached to it.
What Really Goes Into Your Permanent Disability Rating
Your PD rating isn’t random. It comes from a formula that includes:
Whole Person Impairment (your baseline medical rating)
Your age
Your job
Any pre-existing conditions
Whether medical treatment made your condition worse
How your injuries affect your ability to work
And here’s the hard truth: The wrong doctor or wrong report can lower your PD rating and cost you thousands.
If you haven’t read it yet, don’t miss this helpful guide: The QME Preparation Tips That Could Save Your Case
Pre-Existing Conditions: Will They Reduce Your Rating?
Not always. Yes, the doctor must consider whether any part of your impairment already existed before your work injury. This is called apportionment.
But California law has evolved, and many injured workers don’t realize how much protection they have.
For example, if work-related medical treatment makes your condition worse, the entire permanent disability can still be attributed to your work injury, even if you had pre-existing issues.
That’s a massive win for injured workers and something insurance companies won’t tell you.
Why the Doctor You See Matters
Some doctors barely take the time to understand your injuries. Others use every tool allowed by law to make sure your impairment is rated as accurately and fairly as possible.
Here’s something most people don’t know: A doctor can use any chapter of the AMA Guides if it better reflects the true extent of your impairment. But many don’t. And when doctors cut corners, injured workers lose out.
If you want a deeper breakdown on how different doctors impact your case, read this: Why one QME appointment can change everything in your case
Your Rating = Your Financial Future
Once your PD rating is finalized, the insurance company must begin paying permanent disability benefits, usually within 14 days of your last temporary disability payment.
If they don’t? They may owe penalties.
If you return to work before your case is resolved, the insurance company may not advance payments, but the money is still building behind the scenes. When your case settles, you receive the amount that is accumulated.
In other words: your permanent disability rating determines the check you receive and the medical care you keep.
That’s why protecting your rating from the very beginning is crucial.
Another resource you’ll find valuable: What to do when the Workers’ Comp Insurance Adjuster calls you
So… How Do You Get the Highest Permanent Disability Rating Allowed by Law?
By understanding what actually affects the rating:
✔ Choosing the right doctor
✔ Documenting every limitation
✔ Knowing how age and job factors change the outcome
✔ Ensuring every injured body part is addressed
✔ Challenging improper apportionment
✔ Preparing for your QME with intention, not guesswork
You don’t have to be an expert, you just need the right information at the right time.
Final Thoughts
Your permanent disability rating isn’t just a percentage. It’s your future income, your future treatment, and your future stability.
And when the system feels confusing or stacked against you, resources like these help you stay informed, protected, and in control of your case.
If you're feeling overwhelmed or unsure about your next steps, you’re not alone. You don’t have to figure it out on your own either. Visit www.pacificworkers.com or call 800-606-6999 for a free consultation
About the Author
Bilal Kassem President and Co-founder
Bilal Kassem is the co-founder of Pacific Workers and a nominee for Applicant Attorney of the Year. With a deep-rooted passion for helping injured workers, Bilal leads with empathy and empowers his team to deliver world-class service from the very first interaction.
With more than a decade of experience navigating medical–legal evaluations, Bilal has become a trusted authority on Permanent Disability Ratings and the California workers’ comp system. He has successfully guided thousands of injured workers through complex QME processes, challenged inaccurate impairment reports, and secured fair disability ratings that reflect the true impact of an injury. His strategic approach and deep knowledge of AMA Guides make him one of the most respected voices in the field.