There's no law to prevent you from seeing any doctor. In fact, so long as you're able to pay for visits, you may find you have even greater flexibility and choice than under an insurance plan. After all, physicians don't usually accept all insurance plans, but just about everyone accepts cash. Even health maintenance organizations (HMOs) that run their own medical facilities such as Kaiser Permanente and Group Health Cooperative allow nonmembers to see physicians by paying cash.
The hardest part about seeing a doctor without insurance is the cost. If you're used to a physician with a private practice in a nice community, chances are her services don't come cheap. Although you can technically remain a patient, your budget might force you to change to a lower-cost provider such as a community medical clinic or county hospital.
Insurance companies usually require doctors to have an official cash rate. Insurance reimbursement systems are based on what a doctor would bill a patient paying cash. In theory, a doctor is not supposed to bill insurance at a higher rate than a cash paying patient. However, there are doctors who bend rules. Talk to your physician or her office manager about a fee that you can afford to pay. Often, when doctors know a patient is uninsured, they'll work out an arrangement to help.
If you find yourself uninsured, look into all your options. Federal, state and county governments have coverage options for those in need. Depending on your finances and household size, you or your family members may be eligible for Medicaid or county health department services. Not every doctor accepts these forms of insurance, but yours might -- and if she does, you may save yourself a lot of money.