Short answer. Not for purposes of the compensation claim. Labor Code Article 186 gives the System the authority to choose or change your physician, hospital, or rehabilitation facility. If you switch to your own provider without its authorization, it is not liable to compensate any worsening of your injury that results.
What the law says
The System shall have the authority to choose or order a change of physician, hospital or rehabilitation facility for the employee
Labor Code, Article 186 — System May Change Providers. Read the full provision →
The System, not the worker, controls the choice of provider
Article 186 places the authority to choose, or to change, your physician, hospital, or rehabilitation facility with the System handling the compensation claim, not with you as the injured employee. That may feel backwards if you already trust a particular doctor, but the provision is written that way deliberately, because the System is the one paying for and administering the medical care connected to the claim, and it wants oversight of who is providing it.
Switching on your own has a real cost
The consequence for going around this is specific and unforgiving: the article says the System “shall not be liable for compensation for any aggravation of the employee's injury or sickness resulting from unauthorized changes by the employee.” That covers not just a change of physician, but also unauthorized changes in “medical services, appliances, supplies, hospitals, rehabilitation facilities.” If your condition worsens after you make an unauthorized switch, that worsening may fall outside what the System will compensate.
What this does not touch
Article 186 governs liability within the compensation system, not your general right to seek medical attention. Nothing in it stops you from consulting another doctor for a second opinion, or from getting treatment on your own account outside the claim. What it controls is narrower: whether the System will treat an unauthorized change as within its responsibility to pay for, especially where that change leads to your injury or sickness getting worse rather than better.
The bar is also narrower than it first reads. What the article withholds is compensation for an aggravation resulting from the unauthorized change. The underlying work injury does not stop being compensable because you saw a doctor of your own choosing; what falls outside the System's responsibility is the additional harm traceable to the change itself.
The practical move is to ask first
If you have concerns about the assigned physician, hospital, or facility, the article's own structure points to the answer: raise it with the System and seek its authorization for a change, rather than switching unilaterally and hoping it is accepted after the fact. An authorized change carries none of the risk described above. An unauthorized one puts the burden of any resulting aggravation on you rather than on the compensation claim.
That makes causation the fact everyone will argue about, so keep the record that answers it: the request you made and the reply you received, the dates on which care moved from one provider to another, and medical records describing your condition before and after. Note too that the authority runs in both directions — the article lets the System order a change as well as approve one, so an employee cannot insist on staying with a provider it has decided to replace.