Medicare Part D Coverage Overview

  • Medicare Part D is the prescription drug coverage program for Medicare beneficiaries.
  • It provides access to a wide range of prescription medications through private insurance plans.
  • Beneficiaries can enroll in standalone Prescription Drug Plans (PDPs) or Medicare Advantage plans with drug coverage (MA-PDs).

Components of Out-of-Pocket Expenses under Part D: 

  • Deductible: The initial amount beneficiaries must pay for covered medications before the plan coverage begins. Not all Part D plans have a deductible, but some do.
  • Copayments/Coinsurance: The fixed amount or percentage beneficiaries pay for each prescription filled after the deductible is met.It varies based on the tier or formulary placement of the medication.
  • Coverage Gap (Donut Hole): After beneficiaries reach a certain spending limit, they enter the coverage gap phase. During this phase, they pay a higher percentage for both brand-name and generic drugs.
  • Catastrophic Coverage: Once beneficiaries’ out-of-pocket spending reaches a specific threshold, they enter the catastrophic coverage phase.In this phase, they pay a reduced copayment or coinsurance for covered medications.

Current Challenges Faced by Medicare Beneficiaries:

  1. High Out-of-Pocket Costs: Copayments, coinsurance, and deductibles can be challenging for beneficiaries on fixed incomes. Expenses for medical services and prescription drugs can quickly add up, impacting beneficiaries’ budgets.
  1. Prescription Drug Costs: Rising drug prices and complex Medicare Part D plans can lead to significant out-of-pocket spending on medications. Beneficiaries with chronic conditions may require multiple medications, further increasing their out-of-pocket expenses.
  1. Coverage Gaps: Medicare Part D “donut hole” can leave beneficiaries responsible for a larger share of prescription drug costs. Crossing the coverage gap threshold can result in sudden spikes in out-of-pocket spending on medications. High out-of-pocket costs may deter beneficiaries from seeking timely medical attention and preventive care. Some beneficiaries may skip or ration medications to reduce expenses, affecting medication adherence and health outcomes.

In today’s complex healthcare landscape, managing out-of-pocket expenses holds a major significance. By effectively managing these expenses, beneficiaries can build financial stability and shield themselves from the unexpected burden of sudden financial hardships and mounting medical debt. Moreover, managing OOP expenses enhances healthcare access and medication adherence. Patients would be able to prioritize their well-being without fear of financial constraints.

Medicare Beneficiaries’ High Out-of-Pocket Cost Burdens – The Stats

  • 56 million people (17% of the U.S. population) rely on Medicare benefits, exposing to high costs and financial burdens.
  • 15 million people spend 20% or more of their incomes on premiums plus medical care, including cost-sharing and uncovered services. 
  • Beneficiaries with incomes below 200 percent of the poverty level (just under $24,000 for a single person) and those with multiple chronic conditions or functional limitations are at significant financial risk.
  • Overall, beneficiaries spent an average of $3,024 per year on out-of-pocket costs.
  • Financial burdens and access gaps highlight the need to approach reform with caution.
  • Already-high burdens suggest restructuring cost-sharing to ensure affordability and to provide relief for low-income beneficiaries.

Medicare Out-of-Pocket Smoothing

Medicare Out-of-Pocket (OOP) smoothing is a provision that evenly spreads healthcare expenses over time for Medicare beneficiaries, aiming to alleviate the financial burden associated with high out-of-pocket costs. 

Eligibility for Out-of-Pocket Smoothing

  • Beneficiaries enrolled in Medicare Part D 
  • Beneficiaries must reach the coverage gap phase (where they face higher OOP costs for prescription medications)

Types of Covered Medical Expenses

  • The smoothing mechanism primarily focuses on prescription drug costs during the coverage gap phase.
  • Covered medical expenses include prescription medications that are part of the beneficiary’s Medicare Part D plan formulary.

Step-by-Step Mechanics of Smoothing:

a. Initial Out-of-Pocket Costs: Beneficiary pays deductibles and copayments/coinsurance for prescription medications as per their Medicare Part D plan.

b. Coverage Gap (Donut Hole): Beneficiary reaches the coverage gap phase where they are responsible for a higher percentage of medication costs.

c. Monthly Smoothing: Instead of paying the full higher percentage during the coverage gap, the smoothing mechanism spreads the additional costs evenly over the remaining months of the year. Beneficiary pays a portion of the coverage gap costs each month, resulting in more predictable monthly expenses.

d. Catastrophic Coverage: Once the beneficiary’s out-of-pocket spending reaches the catastrophic coverage threshold, they transition to the catastrophic coverage phase.

In this phase, the beneficiary pays a lower copayment or coinsurance for covered medications for the remainder of the year.

OOP Smoothing Hypothetical Scenario

  • Initial OOP Costs: Beneficiary pays $300 in deductibles and $20 copayment for medications.
  • Coverage Gap (Donut Hole): Beneficiary enters the coverage gap phase, with an additional $500 in out-of-pocket expenses required for medications.
  • Monthly Smoothing: The smoothing mechanism spreads the $500 coverage gap expenses over the remaining 10 months of the year, resulting in an additional $50 monthly cost.
  • Catastrophic Coverage: After reaching the catastrophic coverage threshold, the beneficiary pays reduced copayments for covered medications.

Calculating and Spreading Medicare Out-of-Pocket Costs

Spreading Out-of-Pocket Costs:

  • Medicare calculates the total out-of-pocket costs incurred during the coverage gap (donut hole) phase.
  • The smoothing mechanism then evenly spreads these costs over the remaining months of the year.

Impact on Monthly Expenses:

Spreading costs result in more predictable and manageable monthly expenses for beneficiaries. Beneficiaries pay a portion of the coverage gap costs each month instead of a large sum in a single month. Monthly expenses become more stable, allowing beneficiaries to budget for healthcare costs more effectively.


  • Hypothetical Coverage Gap Costs: $1,000
  • Number of Remaining Months in the Year: 6
  • Monthly Cost: $1,000 / 6 = $166.67

Advantages of Medicare Out-of-Pocket Smoothing

Financial Predictability:

Smoothing evenly spreads healthcare expenses over time, providing beneficiaries with greater financial predictability. Monthly expenses become more manageable, reducing the risk of sudden financial hardships or medical debt. Beneficiaries can budget more effectively, knowing the predictable monthly costs for their healthcare.

Improved Healthcare Access and Adherence:

Predictable costs encourage beneficiaries to seek timely medical attention and preventive care. With reduced financial burden, beneficiaries are more likely to adhere to prescribed treatments and medications. Improved adherence leads to better disease management and overall health outcomes.

All of these challenges affect patients in multiple ways, including increasing medication costs and decreasing adherence to therapy.[14] About 20% of patients cite PAs for their inability to adhere to their acne medications.[14] PAs also cause downstream costs for patients and insurers when appropriate treatment is delayed or denied.[14] Multiple solutions are needed to improve the PA process in dermatology, along with collaboration among all participants.

Limitations and Considerations of Medicare Out-of-Pocket Smoothing


  • Coverage Gap Threshold: OOP Smoothing only applies once beneficiaries reach the coverage gap (donut hole) phase. Some beneficiaries may face high out-of-pocket costs before reaching this threshold.
  • Prescription Drug Formularies: The effectiveness of smoothing depends on the medications included in the beneficiary’s Medicare Part D plan formulary. If certain medications are not covered, beneficiaries may still experience significant out-of-pocket expenses.

Factors Affecting Effectiveness:

  • Plan Design Variability: The smoothing mechanism effectiveness can vary across different Medicare Part D plans, as each plan may have different coverage and cost-sharing structures.
  • Medication Utilization: Beneficiaries’ medication usage patterns impact the effectiveness of smoothing. Those with higher medication needs may still face challenges despite the provision.
  • Financial Constraints: The smoothing mechanism may not fully alleviate the financial burden for beneficiaries with limited financial resources or significant medical expenses.

Kiana Dixson PharmD, BCMAS

Megha Rana PharmDc – Farleigh Dickinson University 2024


  1. Part D Costs Under The Inflation Reduction Act. (2023, February 3). Penn LDI.,more%20evenly%20with%20monthly%20installments
  2. Copeland, L. (2022). Medicare Rights Annual Trends Report Outlines Key Challenges Facing People with Medicare. Medicare Rights Center.
  3. National Academies Press (US). (2018, August 28). Embedding quality within universal health coverage. Crossing the Global Quality Chasm – NCBI Bookshelf.
  4. Drug coverage (Part D) | Medicare. (n.d.).
  5. The National Council on Aging. (n.d.).