In 2003, health care policy makers in Massachusetts agreed that the state should build a system to expand coverage to its uninsured residents.

It took four years before Romneycare was fully up and running.

In between, politicians had to think hard about how they wanted the system to work: how money would be raised and spent, what benefits would be offered, whether and how markets should be used to distribute coverage, whether people who didn’t buy coverage should be penalized. They had to build a computer system to help people check their eligibility and understand their options. They had to recruit insurers to participate. And they needed to find uninsured residents and persuade them to enroll.

A new health care bill before the Senate would require all the states in the country to make a similar soup-to-nuts evaluation of how they’d like their health care systems to work, to build such a system and be ready to open their doors in substantially less time — just over two years. That may not be realistic.

“The answer is absolutely no,” said Jon Kingsdale, who ran Massachusetts Connector, the system that matched Massachusetts residents with health insurance, and is now a public health professor and a consultant. “That’s not enough time for most states to figure it out.”