Understanding the Expense: How much does the SMA shot cost?

October 17, 2025 •

3 min read

Spinal Muscular Atrophy (SMA) has an incidence rate of approximately 1 in every 10,000 live births, and its treatments are among the most expensive medications globally [1.11.4, 1.11.1]. So, exactly how much does the SMA shot cost and what factors determine the price?

Quick Summary

A detailed analysis of the high price of Spinal Muscular Atrophy (SMA) treatments. It covers the one-time cost of Zolgensma, recurring expenses for Spinraza, and the annual price of Evrysdi.

Key Points

Three Main Drugs: The primary treatments for SMA are Zolgensma (one-time infusion), Spinraza (recurring injection), and Evrysdi (daily oral liquid) [1.9.2].
Zolgensma Cost: Zolgensma has a one-time list price of about $2.125 million, making it one of the most expensive drugs in the world [1.5.1].
Spinraza Cost: The 'SMA shot,' Spinraza, costs around $750,000 in the first year and $375,000 for each subsequent year [1.5.3].
Evrysdi Cost: Evrysdi is a daily oral solution with a weight-based annual cost, capped at approximately $340,000 [1.6.1].
Insurance is Crucial: The final out-of-pocket cost for a patient is determined by their insurance plan, including deductibles and co-pays [1.8.4].
Financial Aid Exists: All three drug manufacturers offer co-pay assistance and patient foundations that can significantly reduce patient costs [1.8.1].
Non-Profit Support: Organizations like the PAN Foundation offer grants to help underinsured patients afford their medication [1.7.3].

Understanding Spinal Muscular Atrophy (SMA)

Spinal Muscular Atrophy (SMA) is a rare, inherited neuromuscular disease characterized by the progressive loss of motor neurons, which are nerve cells in the spinal cord [1.7.3, 1.11.4]. This degeneration leads to muscle weakness and atrophy. SMA is caused by a mutation in the survival motor neuron 1 (SMN1) gene [1.11.4]. While there are several types of SMA varying in severity, the development of new medications has transformed the prognosis for many patients [1.11.2]. However, these groundbreaking treatments come with a significant financial burden.

How much does the SMA shot cost? A Breakdown of Treatments

The term 'SMA shot' most directly refers to Spinraza (nusinersen), which is administered via an injection. However, the treatment landscape includes two other major drugs, Zolgensma and Evrysdi, each with a different administration method and cost structure.

Spinraza (nusinersen): The Recurring 'Shot'

Spinraza is an antisense oligonucleotide drug given as an intrathecal injection (into the fluid of the spine) by a healthcare professional [1.10.1, 1.9.2]. Its pricing is based on a recurring schedule.

First Year Cost: The initial treatment involves several loading doses, bringing the first-year list price to approximately $750,000 [1.5.1, 1.5.3].
Annual Maintenance Cost: After the first year, the treatment continues with maintenance doses every four months, costing around $375,000 annually for life [1.5.1, 1.5.3, 1.10.1].

Zolgensma (onasemnogene abeparvovec-xioi): The One-Time Gene Therapy

Zolgensma is not a shot but a one-time gene therapy administered via intravenous infusion [1.9.2]. It is designed to address the genetic root cause of SMA by replacing the function of the missing or nonworking SMN1 gene [1.11.2].

One-Time List Price: Zolgensma is known for being one of the most expensive drugs in the world, with a one-time list price of approximately $2.125 million [1.3.5, 1.5.1]. The manufacturer, Novartis, argues that this high upfront cost is more cost-effective over a decade compared to the cumulative cost of lifelong treatments like Spinraza [1.5.5].

Evrysdi (risdiplam): The Daily Oral Solution

Evrysdi is the first oral medication for SMA, taken daily at home as a liquid solution [1.2.1, 1.6.2]. It offers a less invasive treatment alternative.

Annual Cost: The price of Evrysdi is weight-based. For infants, the cost can be under $100,000 per year, but it increases with weight up to a maximum annual list price of about $340,000 for patients weighing 44 pounds or more [1.6.1, 1.6.4].

Comparison of SMA Treatment Costs and Administration


Feature	Zolgensma (onasemnogene abeparvovec-xioi)	Spinraza (nusinersen)	Evrysdi (risdiplam)
Administration	One-time IV infusion [1.9.2]	Intrathecal injection [1.10.1]	Daily oral liquid [1.2.1]
Frequency	Once in a lifetime [1.2.3]	4 loading doses, then every 4 months [1.10.1]	Daily [1.6.2]
List Price (Approx.)	$2.125 million (one-time) [1.5.1]	$750,000 (Year 1), $375,000 (annually after) [1.5.3]	Up to $340,000+ annually (weight-based) [1.6.1]
Age Approval	Children under 2 years [1.8.3]	All ages [1.10.1]	Adults and children 2+ months [1.6.1]

Factors Influencing Out-of-Pocket Costs

The list price is rarely what a patient pays. The final cost is determined by several factors:

Insurance Coverage: This is the most critical factor. Coverage for these high-cost drugs requires prior authorization and meeting specific clinical criteria set by the insurer [1.8.2, 1.8.3]. Zolgensma and Spinraza are typically covered under the medical benefit, while Evrysdi is covered under the pharmacy benefit [1.8.4].
Deductibles, Co-pays, and Co-insurance: Patients are responsible for a portion of the cost based on their plan's structure. These amounts can still be substantial without additional assistance.
Manufacturer Patient Assistance Programs: All three drug manufacturers (Novartis, Biogen, and Genentech/Roche) offer co-pay programs and patient foundations. For commercially insured patients, these programs can lower out-of-pocket costs to as little as $0, with annual assistance caps [1.8.1]. Uninsured or underinsured patients with qualifying incomes may also receive the medication for free through these foundations [1.8.1].
Non-Profit Organizations: Groups like the PAN Foundation and others provide financial grants to help underinsured patients cover their out-of-pocket expenses for SMA treatment [1.7.3, 1.7.4].

Conclusion: A Complex and Costly Landscape

Answering "how much does the SMA shot cost?" reveals a complex financial landscape. While Spinraza, the actual 'shot,' carries a high recurring annual cost of $375,000, the one-time $2.125 million price tag of Zolgensma and the weight-based annual cost of Evrysdi present different financial challenges [1.5.1, 1.3.5, 1.6.1]. The actual cost to a family is heavily dependent on their insurance plan and their ability to access robust financial assistance programs. These treatments have revolutionized care for a devastating disease, but their high prices continue to fuel debates on drug pricing and healthcare accessibility.

For more information on SMA and patient support, a great resource is Cure SMA.

Frequently Asked Questions

The 'SMA shot' typically refers to Spinraza (nusinersen), which is administered as an intrathecal injection into the spinal fluid four times in the first year and three times a year thereafter [1.5.1, 1.10.2].

The high cost is attributed to factors like extensive research and development for a rare disease, the complexity of manufacturing gene-based therapies, and a value-based pricing model that considers the life-altering benefits of the drugs [1.3.2, 1.4.2].

Zolgensma is a one-time gene therapy that replaces the function of the defective SMN1 gene to halt disease progression. While it provides long-term and sustained benefit, it cannot reverse damage that has already occurred and is not officially termed a 'cure' [1.4.4, 1.2.3].

Yes, most commercial insurance plans, as well as Medicare and Medicaid, cover these treatments, but they require prior authorization and have strict eligibility criteria that patients must meet [1.8.2, 1.8.3, 1.7.1].

For patients with commercial insurance, manufacturer co-pay programs can often reduce the out-of-pocket cost to $0 or a very small amount, up to an annual cap. For uninsured or underinsured patients, foundations may provide the medication for free based on income [1.8.1].

After four initial loading doses, a maintenance dose of Spinraza is administered once every four months, which amounts to three times per year [1.10.1].

Currently, there are no generic alternatives for Zolgensma, Spinraza, or Evrysdi. These are the only three widely approved disease-modifying therapies for Spinal Muscular Atrophy, and all are high-cost specialty drugs [1.6.2].