Hi Jim. Currently, freelance (autonomo) workers may increase their monthly payments (leading to a higher pension) until six months before they turn 50. After that, adjustments may only be downwards. Therefore, most freelancers pay the minimum until they are 49.5 years old and then raise payments to the maximum (or as much as they can afford) and then get a maximum pension at age 65.
However, the system will probably be changed...more than 15 years required, freelancers no longer allowed to pay the minimum but rather in accordance with revenues, no retirement until age 67, etc., etc. You can get more info. at the SS office closest to you. However, if you are well under 49, maybe you don't need to worry yet. If you are close to that age, maybe you need to check out the details...It's hard to be young and poor, but even harder to be old and poor (in my view). So, I agree, it's never too early to plan for the future!