Coming from those countries, you are allowed to enter Costa Rica without any visa and you can stay here for 90 days, the purpose of your stay does not matter at all. The ones who like to stay longer in Costa Rica should leave the country for a period of 72 hours minimum and before the 90 days expire, after this procedure they are allowed to re-enter the country for another 90 days. Leaving e.g. to Panamà or Nicaragua, the traveler generally need to present a departure ticket from Costa Rica to Europe or USA to be able to return to Costa Rica. In case of stopovers in the US, their immigration regulations will apply (see below). Since October 2004 the US immigration only allows machine readable passports should you wish to enter the country not having a visa. This is valid for all travelers and all groups of age.
Since January 12th, 2009 for all travelers from countries that are part of the „Visa Waver Program“ (VWP) it is mandatory to fill out the according form in the Internet before the actual arrival in the US. This electronic immigration application will be charged by the US government with USD 14 (at the moment) and will generate an entry permit after checking with the authorities, the form is to be found on: https://esta.cdp.dhs.gov (Electronic System for Travel Authorization - ESTA)
Due to the actual safety situation and the according regulations of the US American Transportation Security Administration (TSA) air passengers are not allowed to bring liquids or jellies on board or into the security sector of an airport. This includes beverages, shampoos, sunscreens, cremes, tooth paste, styling gel and other similar products. Those articles must be stored in the luggage that is checked in.
Following items can still be taken on board: baby food, breast milk or juice for a baby that is traveling with, prescribed medicine, but the name on the packings must be consistent with the name on the passenger ticket (prescription must be present), Insulin and other necessary non-prescribed medicine. Beverages that are bought in the security section of the airport must be consumed before boarding.
Customs in general observe all trans frontier merchandise traffic. Entering the country, additionally to the customs regulations, also the immigration regulations are to be taken into consideration.
Customs duties in Costa Rica will not be charged on articles that are for personal, private or job-related use, but this applies only as long as the quantity is not assumed to be for commercial purpose. The Costarican law allows the searching of luggage and also stipulates that travelers fill out forms in which they have to declare carried articles such as fruit, vegetable, beef and so on. There is only one custom form to be filled out per family through the family responsible.
Local as well as foreign currencies may be imported without limits. However, currencies exceeding an amount of USD 10.000 must be declared.
At departure there will be due a departure tax for tourists, at the moment the fee is USD 29.-, furthermore an eventual security tax of USD 6 can be added. Both taxes can be paid in USD, CRC or with credit cards. No taxes need to be paid by transit passengers who leave Costa Rica within 12 hours.