I have and it isn't, hence calling them 
Log into your Government Gateway or whatever it's called this week, and look at the State Pensions page. It should tell you what you have currently built up.
If it shows you having £168.60 p/w (or more) then that's it - you have enough NI contributions already to max out what you can get under the new system. You will still have to pay NI if you're in paid employment, but your state pension amount will not increase (other than the yearly inflation linking).
If it shows less than £168.60 p/w then you can still add to it, up to £168.60. You will automatically add £4.80 to your current amount for every future year you work and pay NI. So (say) your current SP amount is shown as £100, then you will have to work/pay NI for another 14.29 years (£68.60/£4.80) to reach the full amount. Providing you expect to work enough years in the future to get to the maximum amount, there is no need to bother with paying for missing years. In my example, provided you are less than 52 and expect to work to 67 then you will build up to the full SP amount.
However, if you have large gaps in your NI record (swanning about the world on gap years, Winter seasons in the alps and sunning yourself in the West Indies in the Summer
) then you may not have enough working years left to build up to the full SP. In that case it can be worth buying back/filling in missing NI years. Choosing which years to buy is complex though, and it's often not worth buying post 2016 years.
