Acute illnesses have a beginning, a course of treatment, and an end. Chronic conditions do not. A patient diagnosed with multiple sclerosis at age 35, or with rheumatoid arthritis at 45, or with diabetes at 50 faces drug costs that accumulate year over year, across decades, with no defined end point. When those annual costs are high — and for many conditions they are very high — the financial burden compounds in ways that aggregate cost figures do not fully capture. This article documents what patients with several major chronic conditions actually spend on drugs, what the research shows about how those costs affect adherence, and how the structure of insurance coverage interacts with chronic care.
Diabetes
Diabetes affects more than 37 million Americans and requires ongoing medication to manage blood glucose levels. The medication landscape is diverse: some patients use only oral agents, which may be generic and inexpensive; others require insulin, newer injectable agents, or combination regimens that can be substantially more costly.
Insulin is the most significant cost driver for patients with Type 1 diabetes and for many with Type 2. GoodRx analysis estimated that the average person with diabetes could spend between $3,300 and $4,600 per year on out-of-pocket costs — including medications, provider visits, and monitoring supplies — even with health insurance. Patients with chronic complications face additional out-of-pocket costs averaging $470 per year on prescription medications and provider visits, with emergency and hospital care adding further costs.
The American Diabetes Association’s 2022 economic analysis estimated total direct medical costs of diagnosed diabetes in the U.S. at $306.6 billion in 2022, though this figure includes all medical costs, not only drug costs.
For Medicare Part D beneficiaries, the Inflation Reduction Act of 2022 included a provision capping out-of-pocket costs for insulin at $35 per month beginning in 2023 — a significant change from the prior structure, under which some patients faced insulin costs of hundreds of dollars per month.
Multiple Sclerosis
Multiple sclerosis is treated primarily with disease-modifying therapies (DMTs), a class of drugs that reduce relapse rates and slow disease progression. The cost of MS DMTs has been one of the most extensively studied examples of high-specialty-drug pricing in the United States.
A 2021 analysis in Therapeutic Advances in Neurological Disorders found that many MS DMTs exceed $90,000 per year in list price, with a median annual cost among available DMTs of $91,835 in 2020. Several products exceed $100,000 per year. The same analysis estimated lifetime direct medical costs of MS at $4.8 million (in 2020 U.S. dollars), making it the second most expensive chronic condition behind heart failure.
Patient out-of-pocket costs, while lower than total drug costs due to insurance coverage, are also substantial and have been rising. Managed Healthcare Executive reported that average out-of-pocket costs for MS DMTs increased 217 percent between 2012 and 2021, rising from $750 per year to $2,378 per year. For patients in high-deductible plans or without adequate coverage, actual out-of-pocket exposure is higher still.
The specific price of Ocrevus (ocrelizumab), a widely used MS biologic for both relapsing and primary progressive MS, has been cited at approximately $65,000 per year in annual drug costs.
HIV
Antiretroviral therapy (ART) for HIV is highly effective at suppressing viral load and preventing transmission, but requires lifelong medication for people living with the virus. The drug regimens used in the United States for HIV — where the treatment standard involves combinations of multiple agents — carry list prices that have increased substantially over time.
A 2020 study in JAMA Internal Medicine found that the annual average wholesale price for ART regimens recommended for most people with HIV ranged from $36,080 to $48,000 per year in 2018, up from $24,970 to $35,160 in 2012. The average cost increased 34 percent over that six-year period — 3.5 times faster than the general inflation rate. The researchers noted that even with new generic options available in 2018, all recommended initial regimens were priced above $36,000 per patient per year.
The monthly AWP for Truvada (emtricitabine/tenofovir disoproxil fumarate), a commonly used component of HIV prevention and treatment regimens, has been reported by WebMD at nearly $1,700 for a 30-day supply. Generic alternatives exist at substantially lower prices, but access and formulary placement vary.
For patients with HIV who lack adequate insurance coverage, the cost of ART — estimated by one analysis at $1,800 to $4,500 per month across a patient’s lifetime — represents a financial commitment that few could manage without assistance programs, Medicaid coverage, or the Ryan White HIV/AIDS Program, which funds care for low-income patients.
Rheumatoid Arthritis
The standard of care for rheumatoid arthritis increasingly relies on biologic drugs — large-molecule therapies that target specific immune pathways. These drugs, which include adalimumab (Humira), etanercept (Enbrel), and several others, carry list prices of approximately $6,000 per month for Humira and similarly high levels for comparable agents. Annual biologic costs for RA patients regularly exceed $50,000 to $80,000 per year at list price.
Patient out-of-pocket costs for RA biologics depend substantially on insurance plan design and the availability of manufacturer copay assistance. For patients with Medicare, where manufacturer copay assistance programs are prohibited under anti-kickback rules (unlike in the commercial market), out-of-pocket exposure before the IRA’s $2,000 cap took effect in 2025 could reach thousands of dollars annually even with Part D coverage.
The biosimilar landscape for RA biologics has begun to change the pricing picture. Biosimilars of Humira began entering the U.S. market in 2023, seven years after biosimilar competition began in Europe. Whether biosimilar prices will translate into lower patient costs depends on formulary placement and insurer contracting — dynamics that are still evolving.
Cancer: Oral Specialty Drugs
The growth of oral cancer medications — targeted therapies, kinase inhibitors, and other specialty agents that can be taken at home rather than administered by infusion — has created a new cost-sharing problem for patients. Under most insurance structures, physician-administered drugs (typically covered under the medical benefit with lower cost-sharing) and pharmacy-dispensed drugs (covered under the pharmacy benefit with deductibles and cost-sharing) are treated differently. Oral cancer drugs generally fall into the pharmacy benefit, exposing patients to higher cost-sharing.
A Vanderbilt University Medical Center study analyzed 10 commonly used oral cancer drugs under Medicare Part D and found that before the IRA’s benefit changes, a Medicare beneficiary without low-income subsidies could expect to spend $10,000 to $15,000 out of pocket for one year of treatment with a single drug. Across the 10 drugs, each would have cost beneficiaries more than $3,000 for the first month’s fill alone.
A more recent University of Michigan analysis found that for Medicare Part D beneficiaries, annual out-of-pocket costs for oral cancer medications averaged $11,284 in 2023 and an estimated $3,927 in 2024, following the IRA’s changes to catastrophic coverage. The median cost saving was $7,260. The same study projects further reductions from the $2,000 Part D out-of-pocket cap that took effect in 2025.
The Medicare Part D Coverage Gap and the IRA Cap
Before the Inflation Reduction Act, Medicare Part D’s benefit structure included a “coverage gap” — informally known as the donut hole — in which beneficiaries were responsible for a higher share of drug costs after their total spending crossed a threshold, until they reached the catastrophic coverage level.
In 2024, Part D beneficiaries had to accumulate $8,000 in out-of-pocket spending to reach the catastrophic phase, where cost-sharing dropped significantly. For patients with multiple chronic conditions requiring expensive medications, years could pass before reaching the catastrophic threshold in a single benefit year, and the threshold reset annually.
The Inflation Reduction Act restructured the Part D benefit to eliminate the coverage gap and cap out-of-pocket costs at $2,000 per year beginning in 2025 (adjusted to $2,100 for 2026). ASPE analysis projected that approximately 11 million Part D enrollees would reach the $2,000 cap in 2025, with average out-of-pocket savings of about $600 per enrollee — and about $1,100 for those not receiving low-income subsidies.
Cost-Driven Non-Adherence: Documented Consequences
Across chronic conditions, research consistently documents that a significant proportion of patients modify or forgo prescribed treatment because of cost. A review published in Preventing Chronic Disease found that the prevalence of cost-related non-adherence (CRN) in the U.S. is high, with 6 to 7 percent of U.S. adults reporting at least one form in a given period, and rates substantially higher among patients with chronic conditions. The same review found that relative to full adherence, CRN is associated with higher mortality rates for patients with diabetes, cardiovascular disease, and hypertension.
A 2023 JAMA Network Open study found that approximately one in five adults aged 65 and older reported experiencing cost-related medication non-adherence in the past year.
The financial consequences of chronic illness extend beyond drug costs alone. Patients who cannot afford medications for chronic conditions often incur higher downstream costs through emergency department visits, hospitalizations, and complications that adequately controlled disease would have prevented. These downstream costs are borne partly by patients, partly by payers, and partly by public programs — a distribution that standard drug cost analyses do not capture.
The cumulative picture across a patient’s lifetime is one of persistent financial pressure that compounds with disease severity and age. A patient with multiple chronic conditions — a common scenario, since many conditions co-occur — faces stacking drug costs across conditions, each with its own cost-sharing structure, assistance program eligibility rules, and formulary dynamics. The IRA’s $2,000 Part D cap addresses one dimension of this problem for Medicare beneficiaries. The broader landscape for commercially insured patients with chronic illness remains substantially unchanged.
This article was researched and drafted with AI assistance under human review. See our full AI and editorial practices.