(Sometimes people call this 2009-2010 law the Health Care Reform Act, ObamaCare, the Affordable Health Care Act, etc.)
Do you want the enrolled bill, the session law, a section number, or a page number? (If the latter, you’ll need to be specific about which version of the law the page number appears.)
This information may help – or so we can hope:
Public Law (PL number): the Patient Protection and Affordable Care Act is P.L. 111-148 (signed into law March 23, 2010)
Session law citation is 124 Stat 119 (and many more): Find quick citations to the enrolled bill, the Statutes at Large (session law), U.S. Code, and to a brief legislative history at the FdSys (formerly known as GPO Access) website.
History & Enrolled bill: Thomas dot gov is a good place to search for different versions of Congressional bills
Additional official versions of the law can be found at: Healthcare dot gov
Sometimes a Wikipedia entry helps a lot, and sometimes not.