Key components of President Obama's historic health care reform are starting to take shape as officials finish drafting regulatory guidance. Unfortunately, certain insurance regulations need revision. Unless the rules governing "essential health benefits" change before they take effect next year, many Americans will not be able to access important, lifesaving medications.

For those who have chronic illnesses like HIV/AIDS, these new regulations could be the difference between health and sickness -- or even life and death.

The Department of Health and Human Services has closed the comment period on rules setting out the essential health benefits, or EHB, that private insurers must cover. As HHS reviews these comments, it is our hope that the department will make some modifications that will benefit patients before they gain coverage through the state-based insurance marketplaces known as "exchanges" set to open in 2014.

This part of the health care law is intended to guarantee all Americans the care they need, but the regulations fall short with regard to prescription drugs.

First, the EHB draft regulations require insurers to cover either one drug in each pharmaceutical category or the same number of drugs covered by the state's "benchmark" plan -- the minimum coverage package a state deems satisfactory. This "one from Column A, one from Column B" approach could prove disastrous for patients who need a specific drug to stay alive.

As someone who works daily with HIV/AIDS patients, I have learned firsthand that they often require specialized treatments to stay on top of their illness and live productive, healthy lives. Not all medications in a category like this one are created equal.

If an HIV patient needs a particular protease inhibitor -- for instance, the Drug "A" -- and the only medication covered in that category is Drug "B," the patient may be forced to pay tens of thousands of dollars out of pocket -- or worse, do without a necessary treatment. The entire point of the reform law is that nobody should have to choose between financial ruin and debilitating illness. And to force patients to forgo treatment in this way would also work against another of its central goals, to control the rise in health care spending.

For a number of chronic illnesses, including HIV/AIDS, patients who stick to their prescribed drug regimen have significantly lower medical costs due to a reduced incidence of hospitalization. Failure to adhere to prescribed treatments already costs the U.S. health care system $290 billion a year, according to the New England Healthcare Institute.

One effective way to reform the drug rules would be to model them on what already works. Medicare's prescription drug benefit, Part D, requires coverage for "all or substantially all drugs" in certain classes such as those that treat people with mental illness, cancer and HIV/AIDS, and for others with certain health conditions. That's the right approach.

Such a broad-based formulary has paid off for the program. Not only has Part D dramatically reduced out-of-pocket drug expenditures for seniors, it's also costing the federal government far less than originally projected.

According to the proposed rule, each plan would have to have an appeals process to help patients gain access to drugs not on their plan, but that is all HHS said about the process. Clearly, a little more definition to what that appeals process must look like is necessary to ensure that the Patient Protection and Affordable Care Act guarantees access to all necessary medicines. Again, we can look to Medicare Part D, which calls for an expedited, time-limited process with emergency filling of prescriptions.

Finally, the rules governing drug coverage must require insurers to cover new drugs as they come onto the market. And new medicines should supplement the older ones on the drug formulary, not replace them.

With these modest changes, HIV/AIDS patients and others who suffer from chronic diseases will be assured of access to the medicines that keep them alive and well. These are the people HHS needs to keep in mind as the department works out the last details of how the new law will work.

Carl Schmid is deputy executive director of the AIDS Institute, a national nonprofit organization that promotes research, public policy, advocacy and education on HIV/AIDS and related health care issues.