Under the ADA (Americans with Disabilites Act) people with HIV are protected from health care discrimination. 

State and local laws may also protect people with HIV from health care discrimination. Under the laws, your doctor or dentist cannot refuse to treat you because you have HIV.

Doctors and dentists are always supposed to use universal precautions when treating all patients. Universal precautions protect medical providers by requiring them to treat all bodily fluids as potentially hazardous. Therefore, medical providers working with bodily fluids should wear gloves and masks, and use proper sterilization and disposal techniques when performing medical procedures involving bodily fluids for all patients.

No. A health care provider is only required to treat a person who is seeking treatment or services within that provider's area of expertise. If the patient falls outside the health care provider's area of specialization, that provider can refer the patient with HIV/AIDS to another provider in an appropriate specialty.

The good news is that the vast majority of physicians are more than willing to work with HIV+ patients!