(CBSNews) COLUMBIA, S.C. -- Dee Martin may wake up on Jan. 1 and find herself in a whole different state.

South Carolina and North Carolina have redrawn the border between the two states with GPS technology that allows them to confirm the boundary lines established under an English king in the 18th century down to the centimeter. But that means the lines drawn decades ago through less exact surveying measures are several hundred feet off.

So Martin, who has a South Carolina address and phone number, really lives in North Carolina. She isn't looking forward to the hassle of changing the deed to her home and her address at the post office. There also is likely a property tax increase. But the biggest problem may come through the homebound health care she gets for her 89-year-old husband. The provider doesn't serve North Carolina and that state's Medicaid may not pay for the service even if they change doctors and nurses.

"We knew it would be cheaper to live in South Carolina. Financially, it is going to be a strain -- our only income is Social Security and we already have to use our meager savings to meet regular expenses," Martin said. "Right now we don't know what is going to last longer -- us or our money."

Nineteen homes are changing states. Three currently in North Carolina will end up in South Carolina, while Martin and 15 others are going to change residency to North Carolina.

Bills finalizing the boundary change are currently in the North Carolina and South Carolina legislatures. North Carolina's Senate has passed its bill, sending it to the House. South Carolina's Senate also took action, although with three days left in South Carolina's annual session it isn't clear whether the bill has time to pass in that state's House.

South Carolina Speaker Pro Tem Tommy Pope represents Martin and others in her predicament -- for now. He said he wants to do more to help the constituents he is about to lose, but that is up to North Carolina.

"Maybe it's a good message for South Carolina, but people are fighting a lot harder to stay in South Carolina than they are in North Carolina," the Republican from York said.

But if North Carolina passes its bill, South Carolina lawmakers said there is little they can do except pass their own proposal or leave the people leaving South Carolina in the lurch.

The bills in both states include several items meant to make it easier for people switching states. North Carolina is allowing their soon-to-no-longer-be residents and their dependents in-state tuition at schools in the University of North Carolina system for the next 10 years, provided they live on the same property. Children who attend a North Carolina K-12 public school but wind up in South Carolina can keep attending that school for free.

"We've done everything we can to accommodate folks," said North Carolina Sen. Tommy Tucker, a Republican from Union County, along the border.

One particularly vexing problem has been the Lake Wylie Minimart convenience store. The store currently sits in South Carolina, allowing it to sell fireworks, beer and gas at least 19 cents cheaper because of lower gas taxes. The more exact boundary says it really is in North Carolina.

North Carolina's bill would allow the store to keep selling beer and wine without approval by voters in North Carolina's Gaston County and sell gasoline with South Carolina's lower motor fuels rate until the store is sold to someone else.

These modern problems can be traced all the way back to 1735 when the king of England sent surveyors to what was then his colonies to draw a boundary between the Carolinas with explicit instructions.

The surveyors used poles and measured chains, determining what direction to head from the sun and stars, doing math in their heads, and putting hatchet blows on trees to mark the boundary. Over time, those trees disappeared and future surveyors might not get the line in the exact place.

The states agreed 20 years ago to redraw the 335-mile North Carolina-South Carolina border from the mountains to the Atlantic Ocean. To alter the border in any way from those 1735 instructions would require an act of Congress.