The Medicare Part D prescription drug program is more popular than ever among those who use and depend on it.

The annual senior satisfaction survey commissioned by Medicare Today found that 88 percent of America’s seniors are satisfied with their Part D coverage, and virtually the same percentage say their Medicare drug plan is a great value. Despite this, lawmakers seem determined to transform this program and, in so doing, undermine the foundational elements that have given millions of seniors and Medicare beneficiaries with disabilities affordable access to the medicines they need.

The Senate made the unfortunate choice to disregard the opinions of seniors by passing its recent budget reconciliation bill. Provisions in the bill would give the federal government unprecedented control over drug pricing for Medicare beneficiaries. And with power over pricing comes control over which medicines will be accessible to seniors. If made into law, the bill would penalize Americans who rely on Medicare Part D coverage, those among us with the most severe health challenges. The House of Representatives must reject this bill.

Price negotiations between insurers and pharmaceutical companies — the only approach the Part D program has taken in determining drug prices in its history — aren’t at all a hindrance to lower drug costs. Rather, this framework has contributed directly to keeping costs lower for Part D enrollees, who have enjoyed relatively stable and affordable Part D monthly premiums for years. If the program as constructed wasn’t working, seniors would say so. Instead, our survey found that 90 percent of drug program beneficiaries feel they have access to both affordable medicines and the medicines they need.

A broad range of medication options is critical to seniors, particularly those battling chronic illnesses like diabetes, heart disease or cancer. All Part D plans must include at least two or more drugs in each therapeutic category, providing patients and their physicians multiple options in case the patient is immune to a particular treatment, or it doesn’t provide the optimal outcome. The Senate’s reconciliation bill would, however, disrupt the program’s free-market structure and potentially limit the number of drugs covered, forcing patients to either pay out-of-pocket for the drug their physicians deem most effective or abandon their treatment plan altogether. In essence, this approach would put Washington in the position of determining if a lifesaving medicine is worth covering, leaving some patients as winners and others facing the possibility of serious health consequences.

Seniors do not back these proposed policies. In the survey, two-thirds of those currently enrolled in Medicare drug coverage said Part D drug plans should directly negotiate with biopharmaceutical companies to set prices instead of letting the government determine prices and deciding which drugs should be covered. What seniors do support is establishing limits on annual out-of-pocket prescription costs. They want patient-friendly policy reforms that ensure affordability at the pharmacy counter without obstructing access or delaying treatment.

In the decade-plus since it was established, the Medicare Part D drug benefit has achieved a level of approval among its users seldom seen by any government program. The program’s congressional creators had the wisdom to use competition among private plans to keep costs low and drug accessibility robust. This structure has worked exceptionally well in keeping seniors healthy by providing affordable medicines. Now, Congress is in the midst of fundamentally changing this invaluable program. Before doing so, members of the House should take a moment to listen to the people who depend on it.