Government spokesman Adam Szłapka said on Tuesday that the new voluntary financial instrument is intended to boost domestic investment and support economic growth.
Under the proposal, any adult in Poland would be able to open at least one such account with a financial institution. Multiple accounts would also be allowed, including umbrella-style arrangements covering different investments, state news agency PAP reported.
The initiative, first announced last year, offers tax incentives to encourage participation. Investments in savings bonds and bank deposits would be tax-exempt up to PLN 25,000, while investments in equities, investment funds and certain bonds would be exempt up to PLN 100,000.
Above those thresholds, funds held in the accounts would be subject to a tax based on their value, calculated at 19 percent of the central bank's reference rate as of October 31 of the preceding year, with a minimum rate of 0.1 percent, according to details announced on Tuesday.
In the first year of operation, planned for 2027, the tax rate on assets is expected to be set at 0.85 percent.
Officials said the system is modelled in part on Sweden's Investment Savings Account (ISK) scheme.
The government plans for the legislation to take effect in January.
Finance and Economy Minister Andrzej Domański has said the proposed "tax-free investment account ... will give Polish households a chance to save and invest efficiently."
Poland's capital gains tax—commonly known as the "Belka tax" after former Finance Minister Marek Belka, who introduced it in 2002—applies to income from interest-bearing assets and securities. It stands at a uniform rate of 19 percent.