Gov. David Ige says a U.S. senator who has been questioning Hawaii’s Medicaid spending under Obamacare is using a “flawed analysis” and has his facts all wrong.

U.S. Sen. Ron Johnson, the Republican chairman of the Senate Committee on Homeland Security and Governmental Affairs, is demanding Medicaid data from Hawaii and seven other states that Johnson says experienced rapid increases in their spending on new Medicaid enrollees from 2014 to 2015.

In a letter to Ige last month, Johnson said federal data show Hawaii spending on new Medicaid enrollees increased by almost 76 percent in one year, while overall spending for Medicaid here is “soaring” under the Affordable Care Act, also known as Obamacare.

In a lengthy state response that the Ige administration publicly released Tuesday, Ige countered that Johnson’s calculations “paint an inaccurate picture of our Medicaid expansion expenditures and growth.” Medicaid is the state- and federally funded health care program for the poor and disabled.

The correct numbers show that the per-person cost of Medicaid in Hawaii actually decreased by 7 percent from 2014 to 2015, while total Medicaid costs in Hawaii grew by about 3 percent to almost $2.06 billion, Ige wrote.

“I am setting the record straight,” Ige said in a written statement. “Hawaii’s overall Medicaid costs per capita are at or below the national average. We have among the lowest rates in the nation. I am proud of our program and its effectiveness in providing our residents with quality health care they can afford.

“Let me be clear. This is not about politics or data. This is about people, their lives and our responsibility to ensure that they receive quality health care,” Ige said.

One of the key provisions of the Affordable Care Act was to expand Medicaid to nearly all people under age 65 who have incomes of less than 138 percent of the federal poverty level.

The federal government usually covers about half the cost of Medicaid in Hawaii, but for Hawaii and other states that expanded Medicaid under the ACA, the federal government has been paying 90 to 100 percent of the cost of the expansion since 2014.

Johnson, R-Wis., said the increased costs of Medicaid under the ACA go far beyond initial projections, and he raised similar concerns about increased Medi­caid spending in California, Illinois, New York, Michigan, New Hampshire, Ohio and West Virginia. He is asking each of those states what they are doing to control costs.

Ige cited data showing Hawaii has “one of the most effective and efficient health care systems in the country,” with lower health care costs, better outcomes and a high proportion of people with health coverage compared with other states.

“I urge you to remember that the Medicaid coverage that you have tried to abolish will deeply impact our citizens — our family members and friends who are integral members of our communities,” Ige wrote in his response to Johnson. “We must put aside partisan politics and work together to ensure health coverage for all.”