But at least early in the broader eligibility phase, appointments will likely be challenging to get. Vaccine supply is still below the level of demand, and if history is any lesson, a crush of new demand could strain or even break signup systems. And as welcome as the broader eligibility might seem on its face, there’s some reason to worry that those disruptions could actually slow down vaccinations, as it did earlier in the rollout.

Quick tips for getting a vaccination appointment

There are dozens of tools and tricks that might help you snag a vaccine appointment, but three pieces of simple advice consistently stand out.

First, be patient, especially right after eligibility expands. Experts in finding vaccinations, and even some states, warn that there will likely be a short period of intense demand as everyone who’s newly eligible tries to get vaccinated immediately. So if you’re disappointed in your first few tries to get an appointment, keep at it.

Second, find a local Facebook vaccine signup group. Among vaccine booking veterans, there’s broad consensus that Facebook groups are the best single source of practical signup advice. In most cases, you’ll want to find one for your county or city, rather than state, because they’ll have more specific information about your local vaccine administrators and their signup processes.

And third, be flexible. If you’re willing to take an appointment thirty miles away or very early in the morning, you’ll find something faster.

States expanding eligibility

Here are the states opening vaccine access to all adults by early April. Keep in mind that pharmacies in many states offer vaccines through separate systems.

Connecticut: All adults in Connecticut will be eligible for vaccine appointments starting Thursday, April 1. Here’s Connecticut’s vaccine signup portal.

Indiana: Residents over 16 will be eligible for the vaccine starting March 31. Indiana offers a vaccine pre-registration site here.

Kansas: All Kansans over 16 are eligible for the coronavirus vaccine starting today, Monday, March 29. Kansas Governor Laura Kelly has recommended residents use vaccinefinder.org to locate nearby appointments.

Louisiana: All Louisiana residents over 16 will be eligible for vaccination starting today, March 29. One Louisiana health system, LCMC, offers signups here.

Minnesota: Any resident 16 or older will be eligible starting on March 30. Minnessota Public Radio has a guide to the state’s vaccine signup systems.

North Dakota: North Dakotan adults are eligible for the vaccine starting today, March 29. The state’s immunization coordinator recommends using vaccinefinder.org to locate appointments.

Ohio: Ohio expands eligibility to those 16 and up starting today, March 29. Ohio’s Get the Shot portal will help you find an appointment.

Oklahoma: All Oklahomans over 16 are eligible for the vaccine starting March 29. Search for appointments at vaccinate.oklahoma.gov.

South Carolina: Any South Carolina resident 16 or older will be eligible starting on Wednesday, March 31. South Carolina offers a vaccine locator portal.

Texas: All Texas residents 16 and older are eligible for vaccination starting today, March 29. Texas has just launched a statewide vaccine signup portal.

Other states are making more modest moves to expand eligibility this week. New York will expand eligibility to all residents over 30 starting March 30. Kentucky and Florida are opening eligibility to all residents 40 or older starting on March 29. California is opening eligibility to residents 50 or older starting Thursday, April 1.

A few other states have already expanded eligibility to all adults, including Alaska, Mississippi, West Virginia, Georgia and Arizona. Other states plan to further expand eligibility soon, including New York, which will expand to all adults next week, and North Carolina, where all adult residents will be eligible for the vaccine starting April 7.

Why are some states opening eligibility earlier?

The Biden administration expects to send states enough vaccine doses to treat all Americans by May 1. But we’re not there yet, and national vaccination rates are still under 20%. So why are some states already throwing open the doors?

Various factors drive eligibility decisions at the state level, including local politics and current infection rates. But one common factor in states’ decision to expand eligibility is confidence that they’ll have a much larger number of doses to distribute very soon. Johnson & Johnson in particular is expected to deliver a large surge of its one-dose vaccine, more than 10 million doses, by early April.

In a handful of cases, expanding eligibility makes sense if a state has been particularly successful in vaccinating people fast. Connecticut and Alaska (which opened eligibility to all adults on March 10) particularly stand out here, with first-dose vaccination rates currently above 33%.

But a more common thread among states expanding eligibility is a high proportion of already-eligible populations who don’t want the vaccine for various reasons. Observers report many open appointments in some parts of rural Texas, for instance, which could lead to expired and wasted vaccine doses. So expanding signups should mean less waste in similar areas.

Will opening up actually mean faster vaccinations?

Expanded eligibility is great news for individuals who suddenly have access to vaccination. But there’s surprising evidence that widening eligibility faster can actually slow the overall process of getting shots in arms. A study released last week found that some states that broadened eligibility first, including Florida and South Carolina, saw slower vaccination rates than states that kept tighter controls. According to the study’s authors, that’s because the larger applicant pool led to jammed phone lines, crashed websites, and general chaos.

Those circumstances may have changed thanks to signup system upgrades and greater vaccine supply, though. So while initial traffic jams are likely, there’s reason to hope they’ll be short-lived.