The Affordable Care Act is codified mainly in two sections of USC.
The "taxing" aspect is implemented within the Internal Revenue Code beginning with the "Requirement to maintain minimum essential coverage." at 26 U.S.C.A. § 5000A (West).
And, the healthcare aspects of the program are codified in The Public Health and Welfare Code beginning § 18091 with the "Requirement to maintain minimum essential coverage; findings" at 42 U.S.C.A. § 18091 (West).
State Health Insurance Exchanges
The regulation of individual state Health Insurance Exchanges begins with 45 C.F.R. § 155.100, Establishment of a State Exchange, which provides that states "may elect to establish an Exchange that facilitates the purchase of health insurance coverage." 45 C.F.R. § 155.100.
Premium Subsidy
26 C.F.R. § 1.36B–2, Treas. Reg. § 1.36B–2 provides "Eligibility for premium tax credit" for those making up to 400% of the poverty level who are not Medicaid eligible. 26 C.F.R. § 1.36B–2.
Existing Group Health Plans May Continue
29 C.F.R. § 2590.715–1251 preserves the right to maintain existing coverage consistent with a business's decision to provide coverage.
The Medicare Program is enacted via Title XVIII of the Social Security Act at 42 USC § 1395 et seq.
The implementation of the Medicare Program via the Center for Medicare and Medicaid Services (CMS) is at 42 CFR 400.200 et seq.
The TriCare Program is enacted via 10 U.S.C.A. Subt. A, Pt. II, Ch. 55 beginning at § 1076d.
The TriCare Program which is established for the purpose of implementing a comprehensive managed health care program for the delivery and financing of health care services in the Military Health System is implemented at 32 C.F.R. § 199.17.
42 U.S.C.A. § 300e et seq authorizes the federal standards for Health Maintenance Organizations and defines an HMO as "a public or private entity which is organized under the laws of any State and which (1) provides basic and supplemental health services to its members in the manner prescribed by subsection (b) of this section, and (2) is organized and operated in the manner prescribed by subsection (c) of this section." 42 U.S.C.A. § 300e (West)