Maryland has launched a single portal for people to register for coronavirus vaccinations at mass vaccination sites, amid frustration with the state’s decentralized system and criticism from Democrats over racial disparities in who is getting the vaccine.

The website, covidvax.maryland.gov, will not replace local distribution systems but will allow people who qualify for a shot under the state’s Phase 1 criteria to preregister for an appointment at one of six mass vaccination sites.

People also can preregister for an appointment at one of the mass vaccination sites by calling 855-634-6829.

Those who register will then be notified when an appointment becomes available.

Phase 1 includes people 65 and over, people with intellectual or mental disabilities, group housing residents, first responders, health-care workers, school staff, clergy and other essential workers.

Gov. Larry Hogan (R) has faced criticism from Democratic leaders and complaints from residents over a vaccine rollout that has favored rural and White Marylanders over urban and Black residents of the state.

Rural counties have received nearly twice as many vaccine doses per capita than several more-populous jurisdictions in the center of the state. Prince George’s County has the most coronavirus cases in the state but the fewest number of vaccinated residents. Nearly a third of Maryland residents are Black, but only 16 percent of shots have gone to Black people.

None of the mass vaccination sites set up so far are in Montgomery County, despite appeals from leaders in the state’s most populous jurisdiction. But Montgomery residents have claimed the largest share of appointments at the Six Flags mass vaccination site, in neighboring Prince George’s.

Maryland officials have expressed optimism about the mass vaccination sites as a way to ramp up distribution as more doses become available.