The White House is proposing to curtail two popular tax-planning techniques used by the wealthy, but wealth advisers say the strategies will remain attractive even if the new curbs are enacted.

The changes to estate- and gift-tax rules, which the administration says would raise $24 billion over the next 10 years, would be used to help pay for a broad health-care overhaul. It remains to be seen whether members of Congress will get behind President Barack Obama's proposals.

One particular strategy the Obama administration wants to rein in has allowed some wealthy families to pass on tens of millions of dollars to their heirs free of gift and estate taxes, especially since the Internal Revenue Service in 2000 lost a high-profile legal challenge.

In that case, the IRS challenged a trust set up by Audrey Walton, ex-wife of Wal-Mart Stores Inc. co-founder Bud Walton. She used a vehicle, known as a grantor-retained annuity trust, or GRAT, that potentially allows the grantor of a trust to pass on much of the appreciation of an asset to heirs free of gift tax.

The trust works by paying an annuity back to the grantor that, over the life of the trust, adds up to the initial value of the asset plus an interest rate published by the IRS. The annuity isn't taxed, since it simply flows back to the creator of the trust.

If the asset outperforms the IRS-set rate of return, there will be a remainder in the trust. That remainder can be transferred to the trust beneficiaries without incurring gift tax.

However, if the trust grantor dies during the term of the trust, the asset reverts back to the grantor's estate and is subject to the estate tax.

To minimize the risk of that happening, GRATs with a term of as little as two years have been proliferating, the Obama administration said Monday.

If not for the GRAT structure, any gifts exceeding a $1 million lifetime limit would be subject to a 45% gift tax, at current rates.

The administration proposed to set a minimum term of 10 years for GRATs, which might make wealthy estate owners considering such a trust weigh the risk that they won't survive the 10-year term.

But that change will be far more palatable to the wealthy than limits on the amount of return that can be passed on to beneficiaries tax-free, according to Justin Ransome, a partner in accounting firm Grant Thornton's national tax office.

"This doesn't take the GRAT off the planning table for our higher net worth individuals," Mr. Ransome said. "Even if they don't outlive the 10-year term, it's no skin off their nose," he said.

Mr. Ransome said the restriction, however, might encourage estate owners older than 75 -- who would be more at risk of dying during the 10-year trust period -- to consider other planning techniques.

A second Obama proposal aims to limit the ability of wealthy families to use partnership structures to minimize the valuation of assets for estate-tax purposes.

A wealthy family might set up such a partnership for a variety of reasons, including to introduce a younger family member to investing while the parents maintain control over the asset, or to account for the possibility of divorce, said Ronald D. Aucutt, a partner at the law firm of McGuire Woods LLP.

Restrictions that apply -- including a partner's ability to take a distribution, or to transfer part of an asset without the consent of the general partner -- reduce the value of that partner's stake. Accordingly, families discount the assets in the partnership by as much as 40% when valuing it for estate-tax purposes.

"Currently, some transfers are subject to restrictions that the family not only has the capability of removing, but has every intention of removing when it has the chance," said Mr. Aucutt. "The administration sees that as inappropriate and abusive, and it's hard to disagree."

But Greg Rosica, a tax partner at Ernst & Young, said the Treasury proposal might be an over-reach.

"If I've got a $5,000 asset that is subject to certain restrictions, and I don't have a lot of say in decisions about that asset, you're not going to pay me $5,000 for it, because I can't convert it to cash," he said. "Depending upon the circumstances, this could disregard some real restrictions that have an impact on the value of the asset."