For what it's worth... I have Rentista residency. Initial membership and payment to the Caja was, yes, required before you could get your ID (DIMEX). I had a lawyer, for a hundred bucks, go with me to sign up for the Caja (in San Ramon) ... he helped me to opt-out of the 'pension' portion of the Caja because I will have a pension from the USA when I am of age. It wasn't hard... they just don't tell you that you CAN opt-out... but I'm proof that you can opt-out ... and it saved me upwards of $200/month.
I continue to pay the Caja monthly... my cost is 125,000 colones per month... it has gone up a total of 7 colones (which is less than 2 cents) since I started over 4 years ago.
As a rentista resident... I had to RENEW my Residency (and thus, the DIMEX) after 2 full years of 'legal' accepted, residency. In order to renew, I had to show my financial obligations; and I had to show my receipts from paying into the Caja every month for the 2 years... thus, 24 receipts. I pay electronically thru my bank, so the bank printed out a receipt showing the payments. Without proof that you have been a paying member of the Caja for your first 2 years, you can't renew your residency. Thus, you ID will be dead and you'll be forced to leave every 180 days. Make sure, if that is your case, to 'leave' before your ID expires because if both that and your most recent Passport stamp are expired; you will have to pay a fine just to LEAVE the country... and it will be really hard to return.
After you renew, if that is a possibility for you, you can wait until your third year is completed, and then go to Migracion and apply for Permanent Residency. It requires a current ID, a letter explaining why you wish to live here permanently, and a $200 fee (USA). And then you wait. Usually, it gets approved sometime during your 4th year... but not guaranteed. So, you may even need to Renew again... dealing with all of the caja receipts, financial 'proof' letters; etc.
It most likely works differently for other types of residency, like Pensionista, but the basics are the same. Proof of Caja payments is needed to renew Residency. There's always a chance that they won't ask you for the caja receipts when renewing, especially if you renew at a BCR bank... but why take the chance? They didn't ask me for my Caja receipts, but because I went thru the trouble of getting them, I offered them to the woman and she accepted them. AT BCR they basically want your financial documents based on type of Residency, Current Passport, and $$ to renew. They also took my picture for the new ID and I picked it up a few months later at Correos de CR.
Of course, you can live here without Residency if you leave every 180 days... not a terrible thing. You will not have a CR identification card ? nor will you be in the national healthcare system. (free 'ok' healthcare, free prescriptions, free hospitalization) You can pay for a private system; I hear they are not too expensive. So not really a big deal... just know your Dates... leaving here with an expired ID and expired Passport stamp is a no no. There could also be driver's license issues... but I don't drive so ask somebody else.
Hope this helps 'somebody' .....
Pura Vida
