(Reuters) - Will Obamacare's launch look more like Black Friday, when U.S. shoppers flood retail stores for bargains the day after Thanksgiving, or April 15, when procrastinators wait until nearly midnight to file their taxes?
Officials involved in implementing President Barack Obama's healthcare law, academics who study health insurance and benefits experts interviewed by Reuters expect a little of both, with a graph of enrollment timing to be shaped like a lopsided W. They anticipate a fairly busy start as some of the uninsured buy coverage soon after the state-based exchanges open on October 1, followed by a drop-off for several weeks.
A smaller uptick could come just before December 15, the deadline for buying a policy for benefits beginning on January 1, 2014. A final rush of procrastinators is likely ahead of March 31, the last day to buy 2014 coverage and avoid a penalty.
The progress of enrollment will be scrutinized by Obamacare's advocates and foes, as each side will be quick to seize on evidence that the program is working or not. The administration expects to sign up as many as 7 million people via the exchanges for 2014, and needs that number to include about 2.7 million young, healthy participants for the program to work financially.
"We're expecting there will be a big uptake on October 1 and again at the end of the year because people wait until the last minute," said Michael Marchand, spokesman for the Washington Healthplanfinder, that state's Obamacare exchange. "We'll probably also see a big wave in March - 'last call' to buy insurance (for 2014) or be penalized."
Hawaii's exchange, the Hawaii Health Connector, expects a similar pre-Christmas rush. "Given the past patterns of enrollment with other federal programs, consumers tend to wait until the month before the plan benefit period - January 2014 - to enroll and make payment," said Executive Director Coral Andrews, adding that "enrollment numbers at the end of December will" indicate whether Obamacare is working in the president's birth state.
A W-shaped chart would mimic how people have bought health insurance before Obamacare.
"Some people have that natural 'I want to get this done so I'm going to shop October 1,'" said Carrie McLean, director of customer care at online broker eHealthInsurance. But just as many eHealth customers put off shopping for insurance "and think they can call the end of the month and get insurance that starts the first of the following month," she said, so some ACA customers may also procrastinate.
eHealth, which got federal approval to help people shop for Obamacare plans, expects many people to phone its customer service representatives to ask whether a given plan will cover a treatment they need or a medication they're on, and to revisit the exchange website numerous times before signing up for a plan. Waiting to get those answers could push enrollment decisions into late fall.
"I would expect the bulk of the enrollment (for coverage beginning on January 1) to come in November and December," said Jason Alford, director of individual and marketplace sales at Health First, a Florida-based insurer that is selling policies on that state's Obamacare exchange.
Investors surveyed by Citigroup see a slow ramp-up, and lower turnout. They expect 4 million people to buy insurance on states' Obamacare exchanges for 2014, with 500,000 to 650,000 of those in signing up in October.
Obamacare's ground troops are planning for every contingency. "It's not clear at this point what the take-up curve will look like," said Rory O'Sullivan, vice president for research at Young Invincibles, a nonprofit that will help 19-to-34-year-olds, in particular, enroll. "We have six months of open enrollment ahead of us and are in it for the long haul."
Timing "could vary markedly by state depending on a state's unique population and the outreach efforts," he said. For instance, some states have stacked the deck for a "soft opening," with minimal traffic in early October.
Although no other enrollment is identical to that for Obamacare, two of them - workers signing up for employer-sponsored health benefits and enrollment in Medicare Part D prescription drug coverage when it launched in 2005 - come close, and suggest what the exchanges can expect.
According to the Health and Retirement Study, run by the University of Michigan, 11 percent of elderly beneficiaries who signed up for Medicare Part D did so as soon as they could, in November 2005, said Helen Levy, research associate professor at the university.
"Twelve percent waited until the last month (May 2006), and it was more or less smooth between those dates except there was a bit of a bump in January 2006," Levy said.
Health economist Daniel McFadden of the University of California at Berkeley and colleagues have parsed the Medicare Part D data more finely. "The sickest people, with the most to gain, signed up early in the initial enrollment period, but lots of people waited to enroll at the very end," he said. "The take-up rate was the lowest among people who were fairly healthy, poorly educated and had low incomes."
With employer-based health benefits, "a small group enrolls on the first day to get it over with, a lot wait until the last minute, but the vast majority trickle in as they get reminders," said Randall Abbott, a senior healthcare expert at Towers Watson.
That underlines how critical enrollment timing is for both practical and political reasons, including for the perceived and actual success of Obamacare.
Groups that are actively recruiting uninsured 19-to-34-year-olds say peer pressure will play an important role in driving this group's behavior.
"The marketplaces' ability to attract early adopters might create a snowball effect, particularly if people start posting on Facebook and Twitter," said Larry Levitt, a senior vice president at the Kaiser Family Foundation. Conversely, if "none" of their uninsured friends are buying health insurance on their state's exchange, young people may be less likely to do so themselves.
And if Halloween or even Thanksgiving comes and the Obamacare exchanges have netted only a tiny fraction of the projected 7 million, it will provide ammunition for opponents of the Affordable Care Act who say the law is a "train wreck."
Along the way, it will be a challenge to gauge how many people are buying policies on Obamacare exchanges. The administration declined to say when it would announce numbers. Insurers aren't expected to discuss enrollment before they announce first-quarter earnings in early 2014.
Of course, if a state blows through its targets, that will likely be publicized. "If California signs up a million people by Thanksgiving," said Levitt, "I expect we'll hear about it."
Reporting by Sharon Begley and Caroline Humer; Editing by Michele Gershberg and Douglas Royalty