The so-called doughnut hole that many Medicare Part D beneficiaries are finding themselves in with prescription drug coverage isn’t going to disappear for at least 12 years under a current proposal in the U.S. House of Representatives.

Most of today’s 65-year-old beneficiaries will be 79 when the coverage gap between Medicare Part D payments and when lower-cost catastrophic coverage from the government is available, according to an analysis Avalere Health, a Washington, D.C.-based health research firm.

Avalere Health’s analysis also found that although fewer people will fall into the gap from now until 2023, by 2020 some of the sickest Medicare beneficiaries will spend as much as $16,000 on drugs before reaching catastrophic coverage. When a beneficiary reaches the catastrophic level, the government covers 95% of their drug costs.

Seniors are responsible for payments on medications not covered by Medicare between $2,700 and $6,153.75 per year. That hole affects just over a quarter of the Medicare Part D enrollees.

That amount to reach the threshold for catastrophic coverage to become available would increase, the researchers said.

The firm used language proposed in the recent House legislation – part of the overall health care reform debate – and its own analytic models to estimate what would happen to the coverage gap over time if the proposed House legislation on this aspect of Medicare Part D were enacted.

Researchers say the coverage gap will be eliminated over time, but it will likely take 12 years based on the current House proposal. Also, fewer Medicare beneficiaries will fall into the gap over those 12 years, because the legislation increases the rate at which the initial benefit limit and annual out of pocket threshold grow.

People who require multiple medications for chronic conditions, or do not take any biologic or specialty drugs will fare best, the researchers say.