No. Part D plan premiums are not allowed to vary depending on your age, health status, whether you have pre-existing conditions, or are a smoker. The monthly premium that any given Part D plan charges is the same for any beneficiary who chooses to enroll in that plan. If your income is over a certain level, you may be required to pay a higher premium. If you have a relatively low income and limited assets, you may qualify for extra help paying your Part D plan premium and cost-sharing amounts.