In a letter to all insurers offering health insurance policies on, the federal Obamacare marketplace, the Centers for Medicare and Medicaid Services (CMS) yesterday asked the insurance providers to include more federally funded health clinics, safety-net hospitals and other medical providers used by low-income people to their network of service providers.

At the same time, the letter warned that insurers' provider networks will be reviewed to ensure they provide "reasonable access" to health care.