According to article 4 of Decision No. 1639/2006/EC of the European Parliament and of the Council, which establishes the EIP/CIP, the programme is open to the participation of:
- European Free Trade Association countries (EFTA) which are members of the European Economic Area (EEA) in accordance with the conditions laid down in the EEA Agreement.
As a result Norway, Iceland and Liechtenstein are effectively participating in the programme (without the necessity of a specific Memorandum of Understanding)
Croatia was the first external country to join EIP / CIP. On 1 October 2007, the Ambassador of Croatia, H.E. Branko Baricevic, signed the Memorandum of Understanding with Vice President Günter Verheugen.
- Accession countries and candidate countries benefiting from a pre-accession strategy, in accordance with the general principles and general terms and conditions for the participation of those countries in Community programmes established in the respective Framework Agreements and Association Council Decisions.
Under this article, Croatia and the former Yugoslav Republic of Macedonia joined the programme in 2007 and Turkey joined the programme in 2008.
- Countries of the Western Balkans, in accordance with the provisions to be determined with those countries following the establishment of Framework Agreements concerning their participation in Community programmes.
Under this article, Serbia, Montenegro and Albania joined in 2008.
- Other third countries, when Agreements and procedures so allow.
This last article allowed Israel to join the programme in 2007. Other countries, particularly those participating in the European Neighbourhood Policy, in the framework of which the types of Agreements referred to under article 4 (d) are in the process of being developed and signed, may possibly join in subsequent years.