No one but President Obama knows, but nothing in the ACA or the Health Care and Education Reconciliation Act that followed caused a health plan to lose its grandfathered status.
The President's remarks at the GOP House Issues Conference in Baltimore seem to indicate that he was specifically speaking about provisions that were in the bill that they were working on eliminating, but couldn't without going back to the floor of Congress. He gives as an example, the pledge that you can keep the health insurance you have, as a pledge that was violated by a provision of the Affordable Care Act.
If you look at the package that we've presented -- and there's some stray cats and dogs that got in there that we were eliminating, we were in the process of eliminating. For example, we said from the start that it was going to be important for us to be consistent in saying to people if you can have your -- if you want to keep the health insurance you got, you can keep it, that you're not going to have anybody getting in between you and your doctor in your decision making. And I think that some of the provisions that got snuck in might have violated that pledge.
ABC News sought clarification about specifically which provisions he was referring to in the Affordable Care Act (ACA), but got no response.
White House officials did not respond when asked specifically what provisions the president was referring to and how they got added to the bill.
So, the best we can do is to take Obama at his word, that some provision of the ACA in the final law prevents you from keeping the plan you have. The ACA only mentions "grandfathered" health plan in 32 places, none of which determine the grandfathered status of a health plan:
Section 1251.(e): It loosely defines a 'grandfathered health plan' as any one which applies.
Section 1312.: multiple times to exclude them from the risk pool
Section 1311, 1343: to exclude them from risk assessment
Section 1401.: to exclude them from tax credits
Section 5000A.: to include them as essential coverage under the individual mandate
Section 2002.: to allow individuals to remain eligible if they would be considered in eligible by using modified gross income calculation.
Section 2402.: to include projections and extensions of home and community-based services.
Section 3201.: allow rebates under Medicare Advantage
Section 2718.: to include reporting to the Secretary of premiums to losses, and restrict that ratio to 80%-85% or more, as determined by the Secretary.
Section 2709.: to include them in Section 2715 [Uniform Definitions] & 2718 [Ratio & Refunds]
The subsequent law that modifies the ACA, only include 3 instances of grandfathered health plan, none of which determine status:
Section 1231(a)(4)IN GENERAL.—The following provisions of thePublic Health Service Act (as added by this title) shall apply to grandfathered health plans for plan years beginning with the first plan year to which such provisions would otherwise apply:
(i) Section 2708 (relating to excessive waiting periods).
(ii) Those provisions of section 2711 relating to lifetime limits.
(iii) Section 2712 (relating to rescissions).
(iv) Section 2714 (relating to extension of dependent coverage).
(B) PROVISIONS APPLICABLE ONLY TO GROUP HEALTH PLANS.—
(i) PROVISIONS DESCRIBED.—Those provisions of section 2711 relating to annual limits and the provisions of section 2704 [...]
(ii) ADULT CHILD COVERAGE.—For plan years beginning before January 1, 2014, the provisions of section 2714 of the Public Health Service Act [...]
The Health and Human Services Department is ultimately responsible, in their final regulations. Those regulations determined precisely what could be modified without a health plan losing it's grandfathered status.
"These interim final regulations are necessary in order to provide rules that plan sponsors and issuers can use to determine which changes they can make to the terms of the plan or health insurance coverage while retaining their grandfather status"