California’s newly announced expansion of its COVID-19 vaccine campaign — including  six million residents over age 65 — poses brand new challenges for doctors, pharmacies and consumers.

It’s relatively easy to get the vaccine into the arms of health care workers and elderly people who live in residential care settings.

But the new phase brings a new tangle of logistics, for which counties are trying to prepare. What does this mean to you? We’ll try to help by answering these questions.

Q: What just happened?

A: People aged 65 and older are the next group to be eligible to start receiving vaccines.

Until Tuesday, they were behind two other groups: Phase 1A’s healthcare workers and long-term care residents and Phase 1B’s Tier One, which included elders 75 and over, teachers and childcare workers and people who work in food and agriculture.

The 65-year-olds were tucked back in Phase 1B’s Tier Two, which also included essential workers in transportation, some construction and critical manufacturing, as well as the incarcerated and the homeless.

They’ve now jumped ahead in line to join the 75-year-olds, teachers and workers in childcare, food and agriculture, creating one big Tier One.

The other members of Phase 1B’s Tier Two group remain in that group; their situations haven’t changed.

Q: I’m over age 75. Do I wait, along with the 65-year-old crowd, to learn my eligibility?

A: In Santa Clara County, the public health and hospital system is now letting people age 75 and older register for appointments through links available on the County’s website at sccfreevax.org.

Other systems — including Palo Alto Medical Foundation, Stanford, and Kaiser — are expected to expand access to vaccine appointments to their older patients in Santa Clara County soon. Information on how to schedule an appointment with any of these providers is available at sccfreevax.org.

Contra Costa County is letting people age 75 and older register for appointments, too. The online registration system that can be found at https://www.coronavirus.cchealth.org/vaccine.

Alameda County is alerting all residents to fill out a form on https://covid-19.acgov.org/vaccines. San Mateo County doesn’t yet have forms online; for updates, go to https://www.smchealth.org/covid-19-vaccination. For Santa Cruz County, look for updates at https://www.santacruzhealth.org/.

Q: What’s the fate of everyone else in Phase 1B’s Tier One group? Do they register too? If so, how?

A: We’re clueless; for anyone who isn’t an elder, there’s been no announcement.

Q: Can the state tell me if I’m officially eligible?

A: Sometime next week, the state will unveil a new system to let people know if and when they are eligible to receive a vaccine and how to register to receive a notification by email or text message.

Q: If it tells me I’m eligible – then what?

A: You’ll have several options.

One is to go to your primary care provider to receive the vaccine. All large health systems — including Kaiser, Palo Alto Medical Foundation, public hospitals and clinics, Stanford Healthcare, and many smaller community clinics — will be allocated vaccines to vaccinate their patients as they become eligible.

It is also likely that the large pharmacy chains — such as Walgreens, CVS, Costco and Walmart — may eventually offer COVID-19 vaccinations to eligible people.

Another option is to attend a mass vaccination event. These are now being planned. This new system will offer a way for eligible people to schedule an appointment at one of these events.

Q: If I’m not yet eligible, do I just have to wait?

A: No. This new system will also let you register for an email or text. Then it will notify you when you’re eligible for a vaccine.

Q: If I’m in the first group, Phase 1A — as a health care worker or long-term care resident — does this mean I’ve lost my place in line?

A: No, you are still eligible to receive the vaccines.

Q: Do we have enough vaccines to protect all these new people?

A: We don’t yet know, because counties haven’t heard from the state and federal government about how much additional vaccine they will receive in the coming weeks.

But supplies are expected to greatly increase. That’s because the federal government is releasing doses that they were holding back for second doses. And in February or March, two new vaccines — one from manufacturer AstraZeneca, the other from Johnson & Johnson — are expected to debut.

When the providers have an increased supply of vaccine, we expect eligibility will further expand.