insurance plans from various state-specific laws, particularly contract and tort law, to create federal uniformity; , about 60% of insured employees in the US were in self-funded plans subject to ERISA. ERISA has led to tension with reforms which partner with the states, such as the Patient Protection and Affordable Care Act. There have been several significant amendments to ERISA concerning health benefit plans: The Consolidated Omnibus Budget Reconciliation Act of 1985 (COBRA) provides some employees and beneficiaries with the right to continue their coverage under an employer-sponsored group health benefit plan for a limited time after the occurrence of certain events that would otherwise cause termination of such coverage, such as the loss of employment. The Health Insurance Portability and Accountability Act of 1996 (HIPAA) prohibits a health benefit plan from refusing to cover an employee's pre-existing medical conditions in some circumstances. It also bars health benefit plans from certain types of discrimination on the basis of health status, genetic information, or disability. Other relevant amendments to ERISA include the Newborns' and Mothers' Health Protection Act, the Mental Health Parity Act, and the Women's Health and Cancer Rights Act. During the 1990s and 2000s, many employers who promised lifetime health coverage to their retirees limited or eliminated those benefits. ERISA does not provide for vesting of health care benefits in the way that employees become vested in their accrued pension benefits. Employees and retirees who were promised lifetime health coverage may be able to enforce those promises by suing the employer for breach of contract, or by challenging the right of the health benefit plan to change its plan documents to eliminate promised benefits. Pension vesting Before ERISA, some defined benefit pension plans required decades of service before an employee's benefit became vested. It was not unusual for a plan to provide no benefit at all to an employee who left employment before the specified retirement age (e.g. 65), regardless of the length of the employee's service. Under the Pension Protection Act of 2006, employer contributions made after 2006 to a defined contribution plan must become vested at 100% after three years or under a 2nd-6th year gradual-vesting schedule (20% per year beginning with the second year of service, i.e. 100% after six years). (ref. 120 Stat. 988 of the Pension Protection Act of 2006.) The Technical Explanation of H.R.4, of the PPA, Page 156 Vesting Rules, states that