Given the state of gridlock in Washington, with a GOP-controlled Congress and Democratic White House working in opposition to each other, most proposals form one side or another can be considered dead on arrival. In that state of affairs, it’s the most easily overlooked provisions that sometimes have the best chance of sneaking through to passage.

President Obama’s 2015 budget contains a change to the little-known Crummey powers, which allow people to put assets into certain trust without invoking gift taxes. This is the kind of low-priority change that might actually get through Congress — and that could significantly impact some estate planning clients.

Crummey powers give a trust holder the right to make gifts to his or her trust that are excluded from gift tax, up to the $14,000 annual limit per gift. To have those payments count as gifts rather than as assets that have been put into the trust, the trust holder agrees to set up a window in which the trust’s beneficiaries are entitled to withdraw those amounts. Without establishing that Crummey power, all gifts made to an irrevocable trust will be subject to gift tax.

Trust holders are currently allowed to give as many as $14,000 gifts to a trust per year as they so choose, as long as each gift recipient gets the Crummey powers to withdraw the funds. The budget proposal would change that to an annual limit of $50,000 per donor.

This proposal is primarily intended to curb contributions to pay insurance premiums on trusts that hold life insurance. As a report from the law firm Katten Muchin Rosenman notes, “The ability to use essentially unlimited numbers of individuals named as Crummey Power holders to absorb the cost of insurance premiums on trust-owned life insurance (so long as the individual has a contingent remainder interest in the trust) has long been viewed as abusive by the Internal Revenue Service.”

Crummey powers are not widely reported on, but they are a key tactic for many people establishing irrevocable trusts. In addition to using it to fund insurance, those gifts to the irrevocable trust can reduce the size of the final estate, reducing or averting estate tax.  If they incur gift tax, those benefits are obviously reduced.

Crummey rights are already very limited. When a trust holder makes a “gift” of funds to an irrevocable trust with Crummey powers, the trustee must then give adequate notice to beneficiaries, alerting them that the funds may be withdrawn.

For Crummey powers to be legal, the beneficiaries must have real withdrawal rights. The trust holder is allowed to counsel them, making them aware of the advantages of keeping their assets in the trust, but he or she cannot have an agreement with the beneficiaries that they won’t exercise those withdrawal rights.

Because the possibility of withdrawal has to be real, the trust must contain sufficient liquid assets so that beneficiaries can exercise their withdrawal rights within the chosen time frame. The IRS has approved 30 days as a sufficient window in which beneficiaries can exercise their Crummy rights, although three days has been ruled out as too brief.

That can be a problem for people who set up the vehicle as an irrevocable life insurance trust (ILIT) for the purpose of funding it with insurance premiums. If the trust holder makes annual “gifts” covered by the $14,000 limit to pay the life insurance premiums, those funds won’t be liquid. Without additional assets, the trust would not have enough liquid funds to satisfy a withdrawal request.

One other concern, which is already extant: The IRS’s 5&5 rule kicks in when a beneficiary’s withdrawal rights exceed the greater of $5,000 or 5 percent of the trust principal. In that situation, the beneficiary may become a trust grantor, and that could trigger gift and income tax consequences that are likely to be counter to the trust holder’s intentions.

Crummey powers are already tricky to establish, and the proposed changes to the rules could make them lose one of their key attributes. Since they’re not widely known, estate planners may want to alert their high-net-worth clients of their benefits and potential future limitations.