I don't think it is possible to find a good direct translation of "10-taggarlösning", so I would suggest to keep the Swedish term and write an explanation in parenthesis.

By the way, welcome to proz, Szarlotka:)

Ref 1: "Tjänstemän som arbetar i kollektivavtalsbundna företag, och som dels fyllt 28 år, dels tjänar mer än 379 000 kronor per år (10 prisbasbelopp), kan teckna en så kallad 10-taggarlösning. Det innebär att de kan träffa en överens- kommelse med arbetsgivaren om alternativa pensionslösningar för den del av pensionen som baseras på lön över 290 250 kronor per år (7,5 basbelopp)."

Ref 2: "price base amount - prisbasbelopp" (A dictionary by Statens pensionsverk (SPV)"

I agree with Bjørnar Magnussen that it is not possible to find a good direct translation. Tio taggar originally refers to a particularly luxurious set of elk's antlers, a worthy hunting trophy. Metaphorically it has come to mean highly-paid employees.

Some months ago I translated this term with a paraphrase: "a pension scheme for staff on high salaries", and the customer liked that. That also avoids getting tangled into that uniquely Swedish concept, "price base amounts" and multiples of it, which will all be pretty meaningless to English readers.