This resource goes into depth about auto insurance in Texas, including liability levels:
https://www.tdi.texas.gov/pubs/consumer/cb020.html
From that page, there is content about liability coverage limits:
Liability coverage pays to repair the other driver’s car if you caused the accident. It also pays the other driver’s and his or her passenger’s medical bills and some other expenses. Texas law requires you to have at least $30,000 of coverage for injuries per person, up to a total of $60,000 per accident, and $25,000 of coverage for property damage. This is called 30/60/25 coverage.
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What if the other driver’s limits aren’t high enough to pay my bills?
If the other driver’s policy limits aren’t high enough to pay for all your car repairs, file a claim with your insurance company. Your collision or uninsured/underinsured motorist coverage should pay the difference. If you file a claim with your insurance company, you’ll have to pay a deductible.
If the other driver’s limits aren’t enough to cover all your medical bills, file a claim with your auto insurance company or your health insurance company. Your auto insurance company will use either your PIP coverage, medical payments coverage, or your uninsured/underinsured motorist coverage to pay the difference. You might have to pay a deductible.
It is possible, in certain circumstances if you are liable, that your auto insurance agent may also be able to represent you in court if he/she is a licensed attorney in Texas. You may not wish to do so, but the option does exist for auto accident situations. Here is one such attorney: click here, here and here.