The guidelines and legal requirements for the constitution of the CPA are defined on the basis of the state.  The federal government approved the CPAs in 1995.  Washington was the first state to pass laws allowing formal formation of CPAs. In 1979, Washington changed the practice of pharmaceutical requirements that provide for the formation of “collaborative drug therapy agreements.” [Citation required] Since February 2016, 48 states and Washington D.C have passed laws that allow the availability of CPAs.  The only two states that do not allow cpAs to be made available are Alabama and Delaware.  Alabama pharmacists hoped that a CPA law, House Bill 494, would be passed in 2015.  The bill was introduced by Alabama House Of Representatives Representative Ron Johnson, but died in committee.  Although CPAs are not a prerequisite for the provision of collaborative care, they can be used to improve the efficiency and effectiveness of collaborative care delivery. If they are used to their full potential, CPAs have the opportunity to improve access to medical care, expand services available to patients, improve efficiency and coordination of care, and use the expertise of pharmacists in drug matters to complement the skills and knowledge of other members of the health team.
In 2015, the American College of Clinical Pharmacy (ACCP) published an updated white paper on the management of collaborative drug therapy. CacP regularly publishes updates on this topic, with previous publications in 2003 and 1997. The document describes the recent history of CPAs, legislative advances and discussed payment models for collaborative drug therapy management activities.  For more information on the services provided by the CPA and associated pharmacies, see the following resources. According to health researcher Karen E. Koch, the first initiative of “collaborative management of drug therapy” can be attributed to William A. Zellmers in 1995 in the American Journal of Health-System Pharmacy.  Zellmer argues for the use of the term “collaborative management of drug therapy” instead of “prescription,” and argues that this will make laws that expand the authority of pharmacists tastier for legislators (and physician representatives). The most important is the debate on why pharmacists are interested in extending this authority: improving patient care through interdisciplinary cooperation.
 The modern concept of collaborative practice has been partly derived from the controversial notion of dependent prescribing authority.  A Collaborative Practices Agreement (CPA) is a legal document in the United States that establishes a legal relationship between clinical pharmacists and cooperating physicians, allowing pharmacists to participate in collaborative therapy management (CDTM). As part of the Cooperation Practices Agreement, a CPC has a pre-use of controlled and uncontrolled substances.  Pharmacists can help physicians treat chronic patients in different ways: In the keynote address at the 2013 APhA Annual Meeting, Reid Blackwelder, President of the American Academy of Family Physicians (AAFP), called for a “collaborative vision of health care.”  Starting in 2010, Part B of Medicare will not be reimbursed to pharmacists.  The Pharmacy and Medically Underserved Areas Enhancement Act (H.R.