Does Aetna Cover Knee Injections? Types, Costs, and Precertification

Aetna does cover knee injections, but what gets paid for depends on the type. Cortisone (corticosteroid) injections for knee osteoarthritis are covered routinely and generally do not require prior authorization. Hyaluronic acid injections, also called viscosupplementation, are covered only after you have tried and failed other treatments, and they require precertification. Platelet-rich plasma and stem cell injections are not covered under any Aetna plan.

Cortisone Injections Are the Easiest to Get Covered

Aetna considers intra-articular corticosteroid injections medically necessary for knee osteoarthritis. Standard products like Depo-Medrol (methylprednisolone acetate) and Kenalog (triamcinolone acetonide) do not require prior authorization under Aetna Medicare Advantage plans and carry no step therapy requirements.¹ The policy sets no specific frequency limit for standard corticosteroid injections.² Commercial plans treat these injections the same way.³

Zilretta, an extended-release form of triamcinolone, is handled differently. Aetna’s commercial plans classify it as not medically necessary, concluding that it has not shown meaningful improvement over standard immediate-release corticosteroids.³ On Medicare Advantage, Zilretta is non-preferred and requires prior authorization; the prescriber must document an inadequate response or intolerable adverse reaction to at least two preferred corticosteroid products.⁴ If approved, authorization covers one dose per knee.⁵

Hyaluronic Acid Injections Require You to Try Other Treatments First

Viscosupplementation is covered only for osteoarthritis of the knee, and only after a documented trial of other options. Every hyaluronic acid product on a commercial plan requires precertification, including the preferred brands.⁶

Under Aetna’s commercial criteria, you have to meet all of the following for an initial course:⁷

Knee osteoarthritis confirmed by X-ray findings (joint space narrowing, bone spurs) or by at least five of nine clinical signs such as bony tenderness, crepitus, age over 50, or morning stiffness under 30 minutes.
Knee pain that interferes with daily activities such as walking or standing.
Inadequate response or adverse effects from non-drug treatments like physical therapy, exercise, bracing, insoles, or weight loss.
Inadequate response, intolerance, or a medical reason not to use acetaminophen, NSAIDs, or topical capsaicin for at least three months.
Inadequate response, intolerance, or a contraindication to corticosteroid injections for at least three months.
No scheduled total knee replacement within six months of starting treatment.

If you go straight to hyaluronic acid without physical therapy, pain relievers, and a steroid injection on record, Aetna will deny the request. Additional courses are approved if you still meet those criteria, showed measurable improvement in pain and function from the prior series, and at least six months have passed since the last injection in that series.⁷

Viscosupplementation is not covered for any other joint. Aetna classifies it as experimental for the hip, shoulder, ankle, and for conditions like patellofemoral syndrome or post-arthroscopy recovery. Combinations of hyaluronic acid with corticosteroids, PRP, or stem cells are also classified as experimental; using a local anesthetic solely to numb the injection site is the one allowed addition.⁷

Which Brand Will Your Plan Approve?

Aetna’s own policy acknowledges a lack of reliable evidence that any one brand of viscosupplement is better than another; cost drives the tiering.⁷

On commercial plans, as of the July 2025 program summary, the preferred products are Monovisc, Orthovisc, and Synvisc-One. Other brands, including Durolane, Euflexxa, Gel-One, Gelsyn-3, Genvisc 850, Hyalgan, Hymovis, Supartz FX, Synojoynt, Synvisc, Triluron, TriVisc, and Visco-3, are non-preferred and may require trying a preferred product first.⁸

On Medicare Advantage, the preferred products that do not require prior authorization are Durolane and Synvisc-One (single-injection) and Euflexxa and Synvisc (multi-injection). Non-preferred products need prior authorization and are approved only if you received the requested product within the past year or have documented intolerable reactions to two or more preferred products.⁹

Aetna Better Health Medicaid coverage is the narrowest. As of January 2026, only Gel-One and Visco-3 are covered, the same medical necessity criteria apply, and initial authorization lasts 12 months.¹⁰

PRP, Stem Cell, and Other Regenerative Injections Are Not Covered

Aetna does not pay for platelet-rich plasma injections for any knee condition, including osteoarthritis. The insurer classifies PRP as experimental, investigational, or unproven.¹¹

The same applies across the regenerative category. Adipose-derived stem cell injections, bone marrow plasma injections, autologous blood injections, autologous conditioned serum, stromal vascular fraction injections, and autologous platelet gel used after total knee replacement are all classified as experimental for knee conditions.¹¹ Fat-derived orthobiologic injections and percutaneous calcium phosphate injections for knee osteoarthritis are also not covered.³

Ultrasound Guidance Is Usually Not Covered

If your provider uses ultrasound to guide the needle, Aetna generally will not pay for the imaging. The insurer considers ultrasound guidance for knee joint injections to be of no proven benefit for most patients. The exception is for members who are morbidly obese (BMI above 40), for whom ultrasound-guided knee injections are considered medically necessary.¹²

What You’ll Pay

Out-of-pocket cost for a covered knee injection depends on your specific plan. A few examples give a sense of the range. Under one Aetna Choice POS II plan, a knee injection during a specialist office visit costs a $25 copay with no deductible; if the same injection is done as an outpatient procedure at a facility, the member pays 20% coinsurance after a $2,000 individual deductible.¹³ A State of Illinois Open Access plan charges a $35 copay for a Tier 1 specialist visit with no deductible, 10% coinsurance after a $300 deductible for Tier 2, and 40% coinsurance after a $400 deductible out of network.¹⁴ A Texas CPOS plan charges 20% coinsurance after a $4,000 in-network deductible.¹⁵ Check your plan documents or call the number on your Aetna ID card for exact amounts.

Getting Precertification

For viscosupplementation, your prescribing provider submits the Hyaluronates Injectable Medication Precertification Request (Form GR-68744), documenting the diagnosis, X-ray findings, every treatment that has been tried and failed, and the specific product requested.⁶ Medicare Advantage members use a Medicare-specific version of the form.¹⁶ Requests go in by phone (866-752-7021), fax (888-267-3277), or through the Availity portal.¹⁷

If You’re Denied

Denials for knee injections usually come from one of four problems: no precertification was obtained before the injection, documentation of failed conservative treatments was incomplete, the diagnosis did not meet the clinical policy criteria, or the provider was out of network.¹⁸

The usual first step is a peer-to-peer review, where your treating physician speaks directly with an Aetna medical director. Aetna says this can resolve issues faster than a written appeal. If that does not work, you or your provider can file a formal appeal within 180 days of a medical necessity or experimental/investigational denial. Aetna generally issues a decision within 60 business days.¹⁹

A strong appeal includes full medical records rather than summaries, imaging reports, a detailed physician letter explaining medical necessity, and documentation of every step-therapy treatment attempted. If the internal appeal is also denied, you can request an external review by independent physicians outside Aetna, which typically produces a decision within 30 calendar days.¹⁸

1
Aetna. Aetna Medicare Advantage Part B Preferred Drug List
2
Aetna. Osteoarthritis Medicare Part B Drug Step Criteria
3
Aetna. Clinical Policy Bulletin 0673
4
Aetna. Medicare Zilretta Precertification Request Form
5
Aetna. Zilretta Medicare Part B Drug Criteria
6
Aetna. Hyaluronates Injectable Medication Precertification Request
7
Aetna. Clinical Policy Bulletin 0179 – Viscosupplementation
8
Aetna. Aetna Commercial Clinical Program Summary
9
Aetna. Viscosupplements Medicare Part B Drug Step Criteria
10
Aetna Better Health. Hyaluronates Aetna Medicaid Policy
11
Aetna. Clinical Policy Bulletin 0784
12
Aetna. Clinical Policy Bulletin 0952
13
Ohio School Employees Retirement System. Aetna Choice POS II Summary of Benefits and Coverage
14
Aetna State of Illinois. State of Illinois Open Access Plan Summary of Benefits
15
eHealthInsurance. Aetna CPOS Plan Summary of Benefits
16
Aetna. Medicare Viscosupplementation Precertification Request Form
17
Aetna. Precertification
18
Aetna. Dispute Process
19
Aetna. Disputes and Appeals Overview