Between 2010 and 2015, more than 19 million people in the United States gained health insurance, mostly through key provisions under the Affordable Care Act, according to an analysis by the Urban Institute.

Number of people younger than 65 who became insured in each state, from 2010 to 2015 WASH. ME. 531,000 22,000 MONT. N.D. VT. 54,000 18,000 21,000 ORE. MINN. 54,000 387,000 N.H. 241,000 N.Y. IDAHO WIS. S.D. 106,000 MASS. 968,000 MICH. 104,000 212,000 7,000 75,000 WYO. R.I. 603,000 23,000 116,000 PA. CONN. IOWA NEV. OHIO 481,000 409,000 NEB. N.J. ILL. 138,000 285,000 630,000 38,000 72,000 874,000 DEL. MD. UTAH IND. 24,000 W.VA. CALIF. 277,000 D.C. COLO. 140,000 316,000 155,000 3,849,000 407,000 VA. MO. KAN. KY. 263,000 202,000 132,000 382,000 N.C. TENN. 509,000 ARIZ. OKLA. 251,000 N.M. ARK. S.C. 391,000 181,000 ALA. 182,000 232,000 293,000 188,000 GA. MISS. 554,000 TEX. 147,000 1,749,000 LA. ALASKA 243,000 FLA. 28,000 1,539,000 HAWAII 48,000 Number of people younger than 65 who became insured in each state, from 2010 to 2015 WASH. ME. 531,000 22,000 MONT. N.D. VT. 54,000 18,000 21,000 ORE. MINN. 54,000 387,000 N.H. 241,000 N.Y. IDAHO WIS. S.D. 106,000 MASS. 968,000 104,000 MICH. 212,000 7,000 WYO. 75,000 R.I. 603,000 23,000 PA. 116,000 CONN. IOWA NEV. 481,000 OHIO NEB. 409,000 ILL. N.J. 138,000 285,000 630,000 72,000 874,000 38,000 MD. DEL. UTAH IND. 277,000 W.VA. CALIF. 24,000 140,000 COLO. D.C. 316,000 155,000 3,849,000 407,000 VA. MO. KAN. KY. 263,000 202,000 132,000 382,000 N.C. TENN. 509,000 ARIZ. OKLA. 251,000 N.M. 391,000 ARK. 181,000 S.C. ALA. 182,000 232,000 293,000 188,000 GA. MISS. 554,000 TEX. 147,000 1,749,000 LA. ALASKA 243,000 FLA. 28,000 1,539,000 HAWAII 48,000 Maps show the number of people younger than 65 who became insured, from 2010 to 2015 ME. Northeast 22,000 VT. 21,000 N.H. 54,000 N.Y. MASS. 968,000 106,000 CONN. R.I. 116,000 75,000 PA. N.J. 481,000 409,000 DEL. MD. 38,000 277,000 W.VA. D.C. 155,000 24,000 South VA. KY. 263,000 382,000 N.C. OKLA. TENN. 509,000 181,000 251,000 ARK. 232,000 ALA. S.C. 188,000 293,000 GA. MISS. TEX. 554,000 147,000 1,749,000 LA. FLA. 243,000 1,539,000 Midwest N.D. 18,000 MINN. 241,000 WIS. S.D. MICH. 212,000 7,000 603,000 IOWA OHIO NEB. ILL. 138,000 630,000 72,000 874,000 IND. 316,000 MO. KAN. 202,000 132,000 West WASH. 531,000 MONT. 54,000 ORE. 387,000 IDAHO 104,000 WYO. 23,000 NEV. 285,000 UTAH CALIF. 140,000 COLO. 3,849,000 407,000 ARIZ. N.M. 391,000 182,000 ALASKA 28,000 HAWAII 48,000 Maps show the number of people younger than 65 who became insured, from 2010 to 2015 ME. Northeast 22,000 VT. 21,000 N.H. 54,000 N.Y. MASS. 968,000 106,000 R.I. CONN. 116,000 75,000 PA. N.J. 481,000 409,000 DEL. MD. 38,000 277,000 W.VA. D.C. 155,000 24,000 South VA. KY. 263,000 382,000 N.C. OKLA. TENN. 509,000 181,000 251,000 ARK. 232,000 ALA. S.C. 188,000 293,000 GA. MISS. TEX. 554,000 147,000 1,749,000 LA. FLA. 243,000 1,539,000 Midwest N.D. 18,000 MINN. 241,000 WIS. S.D. MICH. 212,000 7,000 603,000 IOWA OHIO NEB. ILL. 138,000 630,000 72,000 874,000 IND. 316,000 MO. KAN. 202,000 132,000 West WASH. 531,000 MONT. 54,000 ORE. 387,000 IDAHO 104,000 WYO. 23,000 NEV. 285,000 UTAH CALIF. 140,000 COLO. 3,849,000 407,000 ARIZ. N.M. 391,000 182,000 ALASKA 28,000 HAWAII 48,000

Many of the newly insured were not poor enough to qualify for Medicaid but too poor to buy their own coverage. Others were shut out because of pre-existing conditions.

These groups and others make up the millions that the Congressional Budget Office says could lose their coverage under the Republican plans to repeal and possibly replace the Affordable Care Act.

“All of the elements that enabled more people to get insurance under Obamacare — protections for pre-existing conditions, the expansion of Medicaid and subsidies to make insurance more affordable — are potentially at risk under the various options the Senate is debating,” said Larry Levitt, a policy expert at the Kaiser Family Foundation.

Under six Republican proposals that the Congressional Budget Office had analyzed, the number of uninsured in America would increase by 22 million to 32 million people in 10 years — essentially erasing much of the gains made under the Affordable Care Act. A C.B.O. analysis released Wednesday night showed that a “skinny” repeal measure being floated by lawmakers would increase the number by 16 million in 10 years.