Sunday marks the fourth anniversary of the signing of the Affordable Care Act, or Obamacare, however you prefer to describe it. (But Nancy Pelosi clearly prefers the former.)
Votes during the 112th Congress, from 2011-2012:
1. Jan. 19, 2011: The "Health Care and Education Reconciliation Act" would have repealed all of the Affordable Care Act. It passed 245 to 189 with three Democrats voting for it, but was never considered by the Senate.
2. Feb. 19, 2011: The House's version of the fiscal 2011 continuing appropriations bill included several amendments that would have "severely limited" implementation of the law. It passed 221 to 202 with no Democratic votes and was never considered in the Senate.
The next few votes were on amendments added to the appropriations bill:
3. The Rehberg Amendment #575: Prohibited funding for any employee, officer, contractor or grantee of any agencies funded under appropriations for the departments of Health and Human Services and Labor to implement provisions of the law.
4. The King Amendment #267: Ensured that no money included in the appropriations bill would be used to implement the law.
5. The King Amendment #268: Prohibited funding for the pay of officials who implemented the law.
6. The Emerson Amendment #83: Prohibited funding by the Internal Revenue Service to implement or enforce provisions of the law related to the reporting of health insurance coverage.
7. The Price Amendment #409: Prohibited funding for implementing the law's Medical Loss Ratio provision.
8. The Burgess Amendment #200: Prohibited funding at the Center for Consumer Information and Insurance Oversight.
9. The Pitts Amendment #430: Prohibited funding for actions "to specify or define, through regulations, guidelines, or otherwise, essential benefits as required" in the law.
10. The Gardner Amendment #79: Prohibited funding for implementing new exchanges established by the law.
11. The Hayworth Amendment #567: Prohibited funding for implementing the Independent Patient Advisory Board (the so-called "death panel.")
*12. March 3, 2011: The House passed the "Comprehensive 1099 Taxpayer Protection and Repayment of Exchange Subsidy Overpayments Act of 2011" that repealed some 1099 reporting requirements "that placed a financial burden on small businesses and independent contractors." Passed 314 to 112, with 76 Democrats supporting the bill.
13. April 13, 2011: The House voted to repeal the Prevention and Public Health Fund, a key part of the law that Republicans claim is "riddled with wasteful, unaccountable spending." It passed 236 to 183 with four Democrats supporting the proposal.
*14. April 14, 2011: The defense appropriations bill included provisions that repealed “Free Choice Voucher” program, cut $2.2 billion in funding for the Consumer Operated and Oriented Plan and blocked new money to hire additional IRS agents to enforce the law's "individual mandate." The bill passed the House 260 to 167 with 81 Democrats in support and 59 Republicans opposed.
15. April 14, 2011: In a resolution, the House directed the Senate to take a vote defunding all mandatory and discretionary spending tied to the law. It was ignored by the Senate.
16. April 15, 2011: The House passed its version of the fiscal 2012 budget that would have repealed and defunded the law. It passed 235 to 193 on a party-line vote.
17. May 3, 2011: House eliminated the ability of the secretary of Health and Human Services "to have an unlimited tap on the U.S. Treasury related to government mandated health insurance exchanges." Passed 238 to 183, with five Democratic "yes" votes.
18. May 4, 2011: The House voted to repeal a provision of the law that required $200 million to be spent on constructing School-Based Health Centers. Passed 235 to 191.
19. May 24, 2011: The House voted to convert $230 million in mandatory spending for graduate medical education programs into discretionary spending, which would allow medical schools to receive funding through the regular appropriations process. Passed 234 to 185, with three Democrats in support.
*20. Aug. 1, 2011: The House passed the "Budget Control Act of 2011" that cut some mandatory and discretionary spending tied to the law. It passed 269 to 161, cleared the Senate and was later signed by Obama.
21. Oct. 13, 2011: The House passed the "Protect Life Act" that prevented funds in the law, including tax credits, from being used to pay for abortion or abortion coverage. Passed 251 to 172, with 15 supportive Democrats.
*22. Nov. 16, 2011: The House passed -- and Obama later signed into law -- a measure that required certain benefits to be included in the calculation of modified adjusted gross income (MAGI) for determining eligibility for certain health care programs under the law. Passed 405 to 16, with 170 Democrats voting for it.
23. Dec. 13, 2011: The House passed the "Middle Class Tax Relief and Job Creation Act" that extended the “doc fix” through the law's subsidy recapture and reductions to the Prevention and Public Health Fund, among other things. Passed 234 to 193, with 10 Democrats.
*24. Dec. 16, 2011: The House approved -- and Obama later signed -- the 2012 consolidated appropriations bill that cut $400 million from the Consumer Operated and Oriented Plan and $10 million from the Independent Payment Advisory Board. The measure also cut IRS funding by $305 million from the previous fiscal year. It passed 411 to 5 -- the "no" votes were from fiscally conservative Republicans.
25. Feb. 1, 2012: The House voted to repeal the CLASS Act, a long-term care insurance program created by the law, which Republicans believe was "a microcosm for the problems" in the law. Republican lawmakers dismissed the program as a "budget gimmick, insolvent, done behind closed doors" and as a "massive new unsustainable entitlement." Passed 267 to 159 with 28 Democrats on board.
*26. Feb. 17, 2012: The House passed -- and Obama later signed into law -- the "Middle Class Tax Relief and Job Creation Act" that cut $11.6 billion from the law, including $5 billion from the Public Prevention and Health Fund and $2.5 billion in special funding for Louisiana's Medicaid program, which Republicans labeled as a modern-day "Louisiana Purchase." The measure passed 234 to 193, with 10 Democrats in support and 14 Republicans opposed.
27. March 22, 2012: The House voted to repeal the Independent Payment Advisory Board, which Republicans have labeled the "death panel." It passed 223 to 181, with seven Democrats in support.
28. March 29, 2012: The House passed its version of the fiscal 2013 budget that included language repealing and defunding the law. It passed 228 to 191 along party lines.
29. April 27, 2012: The House voted to prevent interest rate increases for certain student loans and sought to offset the costs by repealing the law's Public Prevention and Health Fund. Approved 215 to 195, with 13 Democratic "yes" votes.
30. May 10, 2012: The House voted to replace automatic defense budget cuts by defunding and repealing parts of the law, including Medicaid Maintenance of Effort (MOE) requirements. The measure passed 218 to 199, with 16 Republican "no" votes.
31. June 7, 2012: The House voted to repeal the tax on medical devices, limitations on reimbursements for over-the-counter medications from tax-advantaged accounts for health care and other payments tied to new exchanges. It passed 270 to 146, with 37 Democratic "yes" votes.
*32. June 29, 2012: The House voted on a highway funding bill signed by Obama that made changes to a Medicaid formula that helped Louisiana's Medicaid program and saved $670 million that counted towards the cost of the bill. The measure passed 293 to 127, with 69 Democrats in support.
33. July 11, 2012: In the wake of the U.S. Supreme Court's decision to uphold most of the law, the House voted once again to repeal the law. Obamacare in its entirety in the wake of the Supreme Court decision to uphold the vast majority of the law. The bill passed 244 to 185, with five Democrats in support.
34. Dec. 20, 2012: The House voted again to replace discretionary budget cuts enacted as part of sequestration by defunding and repealing several provisions of the law. The measure passed 215 to 209, with 21 Republicans opposed to the spending measure.
*35. Jan. 1, 2013: The "fiscal cliff" deal passed the House and included provisions repealing the CLASS Act and rescinding $2.3 billion in unobligated funding for the Consumer Operated and Oriented Plan. The measure passed 256 to 171 with 19 Democrats in support.
Votes in the 113th Congress, from 2013 to today:
36. March 21, 2013: The House passed its version of the fiscal 2014 budget that repealed and defunded the law. It passed 221 to 207, with 10 Republicans opposed to the spending measure.
37. May 16, 2013: The House voted to repeal the entire law. It passed 229 to 195, with just two Democrats voting with Republicans.
38. July 17, 2013: The House voted to delay by one year the implementation of the law's employer mandate. Passed 264 to 161 -- with 35 Democrats voting "yes."
39. July 17, 2013: The House voted to delay by one year the implementation of the law's individual mandate. Passed 251 to 174 -- with 22 Democrats voting "yes."
40. Aug. 2, 2013: The House voted to prevent the IRS from implementing or enforcing any part of the law. Passed 232 to 185, with four Democrats on board.
41. Sept. 12, 2013: The House voted to prevent fraudulent benefits claims by requiring that an accurate verification system be in place before subsidies are paid out. Passed 235 to 191.
42. Sept. 20, 2013: As part of the short-term fiscal 2014 continuing resolution, the House voted to fully defund the law by prohibiting discretionary and mandatory spending and rescinding all of its unobligated balances.
43. Sept. 29, 2013: As part of the fiscal 2014 continuing appropriations bill, the House voted to permanently repeal the tax on medical devices.
44. Sept. 29, 2013: In another amendment vote to the appropriations bill, the House voted to delay the law for one year.
45. Sept. 30, 2013: In yet another amendment to the spending bill, the House voted to delay the individual mandate for one year and to require the president, vice president and Cabinet secretaries to join lawmakers and their staffs in buying insurance coverage through exchanges and without access to a taxpayer-funded employer subsidy.
*46. Oct. 17, 2013: As part of the fiscal 2014 continuing resolution that reopened the federal government, the House voted to require that accurate income verification systems be put in place before the law's exchange subsidies are dispersed. The measure passed 285 to 144 and was later signed by Obama.
47. Nov. 15, 2013: In response to Obama's previous statements that Americans could keep their health-care plan if they liked it, the House voted to allow Americans to do so without being penalized under the law's individual mandate. The measure passed 261 to 157 with 39 Democrats voting "yes."
48. Jan. 10, 2014: The House voted to require the government to notify people who's personal information was breached by using HealthCare.gov. The measure passed 291 to 122, with 67 Democrats voting "yes."
49. Jan. 16, 2014: The House voted to require the Obama administration to provide weekly reporting on "key metrics" to lawmakers and state officials. It passed 259 to 154, with 33 Democrats on board.
50. March 5, 2014: The House approved the "Simple Fairness Act," which would have delayed implementation of the penalty for failing to comply with the law's individual mandate. The measure passed 250 to 160, with 27 Democrats in support.
51. March 11, 2014: The House approved the "Protecting Volunteer Firefighters and Emergency Responders Act," which sought to ensure that volunteer firefighters are not counted as employees under the law's "shared responsibility requirements." The measure passed unanimously.
52. March 11, 2014: The House voted to approve the "Hire More Heroes Act," which would allow employers to exempt any workers with health coverage under TRICARE from being taken into account as part of the law's employer mandate. It passed 406 to 1, with only Rep. Jerrold Nadler (D-N.Y.) voting no.
53. March 12, 2014: The House unanimously approved the "EACH Act," which would provide additional religious exemptions from the law.
54. March 14, 2014: The House voted to repeal the Medicare sustainable growth rate and make improvements to Medicare payments made to physicians and other medical professionals. It passed 238 to 181 with 12 Democratic "yes" votes.
UPDATE/RELATED: While the House has voted 54 times to make changes to the law0, the Obama administration also has instituted a series of delays and other changes to the way the law works in practice. Many of the changes have upset lawmakers, who believe that Congress -- not the administration acting on its own -- should be codifying changes in legislation. Review this timeline of the major changes, as compiled by The Post's senior health-care reporter, Amy Goldstein.