Medicare Coverage for Kidney Stones: Procedures, Prevention Drugs, and What You’ll Pay

Kidney stones are one of the most painful conditions a person can experience — and one of the most common urological problems in the Medicare-age population. About 11 percent of men and 6 percent of women in the United States will develop a kidney stone at some point, with peak incidence in the 40s through 70s. For Medicare beneficiaries, a stone can mean an emergency department visit, outpatient surgery, a temporary ureteral stent, follow-up metabolic testing, and months of prevention medications — all of it generating costs that depend heavily on which part of Medicare applies and whether you carry a supplement.

The good news is that Medicare covers the full spectrum of kidney stone care: diagnostic imaging, procedures to remove or fragment stones, and the prescription drugs used to prevent recurrence. The less obvious news is that the bills arrive from multiple payers — Part A, Part B, and Part D — and the cost-sharing structure differs for each. Understanding the rules before you need them is the highest-value thing a stone-former can do.

Who Gets Kidney Stones and Why Medicare Age Matters

Kidney stones form when mineral salts in urine concentrate and crystallize in the kidneys or urinary tract. The four main types are:

• Calcium oxalate (most common, ~70–80% of stones): driven by high dietary oxalate, low urine volume, hypercalciuria, or low citrate excretion
• Calcium phosphate (~10–15%): associated with renal tubular acidosis and primary hyperparathyroidism
• Uric acid (~8–10%): strongly associated with gout, obesity, diabetes, and metabolic syndrome — all common at Medicare age
• Struvite (infection stones, ~5–10%): caused by urease-producing bacteria; more common in women with recurrent UTIs

Several factors that become more prevalent at Medicare age drive higher stone risk: reduced fluid intake, lower mobility, diabetes, gout, obesity, chronic kidney disease, and medications that raise urine calcium (such as loop diuretics and calcium supplements). Uric acid stones are specifically worth flagging — they are strongly associated with the insulin resistance that underlies type 2 diabetes, which affects nearly 30 percent of Medicare beneficiaries. See Medicare coverage for kidney disease for how recurrent stone disease can progress to chronic kidney impairment.

Part B: Diagnostic Imaging and Laboratory Workup

When a patient presents with flank pain, hematuria, and nausea — the classic triad of renal colic — Medicare Part B covers the diagnostic evaluation:

CT scan (non-contrast): The gold-standard test for acute kidney stone. A low-dose non-contrast CT of the abdomen and pelvis (CPT 74178) can identify stones as small as 1–2 mm, locate them precisely in the kidney or ureter, and measure stone density (Hounsfield units) and skin-to-stone distance — information used to plan treatment. Medicare Part B covers this 80/20 after the annual deductible.

Kidney, ureter, and bladder X-ray (KUB): A plain abdominal X-ray (CPT 74020) can detect radiopaque calcium stones but misses uric acid stones (which are radiolucent) and small stones. It is used for follow-up monitoring in known calcium stone formers.

Renal ultrasound: Preferred for pregnant women and patients with radiation concerns. Ultrasound (CPT 76770) identifies hydronephrosis (ureteral obstruction) reliably but misses smaller stones. Covered under Part B.

Laboratory workup: A standard stone workup includes urinalysis with microscopy (CPT 81001), basic metabolic panel (BMP, CPT 80048), and complete blood count. These are covered under Part B when medically necessary. Serum uric acid, parathyroid hormone (PTH), and calcium are often checked to identify underlying metabolic conditions.

Your cost: In a standard outpatient or emergency setting, you pay 20% of the Medicare-approved amount after the Part B deductible ($257 in 2026). Emergency department facility fees are also subject to 20% coinsurance. Medigap Plan G covers all Part B coinsurance after the annual deductible.

Part B: Acute Stone Attack — Emergency and Observation Care

Most acute kidney stone episodes are managed initially in the emergency department or urgent care setting. Medicare Part B covers physician services; emergency facility charges bill under Part A (if admitted) or Part B (if treated as outpatient/observation).

Pain management: IV ketorolac (an NSAID), IV morphine or hydromorphone, and anti-nausea medications (ondansetron, prochlorperazine) are the standard ED regimen. These drugs are administered in the facility and therefore covered under Part B as incident-to physician services — not Part D.

Medical expulsive therapy (MET): For stones 5–10 mm in the distal ureter, urologists often prescribe an alpha blocker — most commonly tamsulosin (Flomax) — to relax the ureteral smooth muscle and facilitate spontaneous passage. Generic tamsulosin is covered under Part D (typically Tier 1, ~$5–$10/month). Stones under 5 mm pass spontaneously in about 90% of cases without medication; stones over 10 mm almost never pass without intervention.

Observation vs. inpatient admission: For uncomplicated stones managed conservatively, patients are often treated as outpatient or placed in observation status. Observation status is technically outpatient and bills under Part B — you pay 20% coinsurance — rather than the Part A inpatient deductible. If you need IV antibiotics for an infected obstructed kidney (a urological emergency requiring urgent decompression) and the physician determines you need more than two midnights of hospital-level care, you qualify for inpatient admission under Part A. The billing classification matters; confirm it if you are hospitalized.

Part B: Kidney Stone Removal Procedures

When a stone will not or cannot pass on its own — because it is too large, is causing persistent obstruction, or has produced an infected obstructed kidney — Medicare Part B covers three main interventional approaches.

Extracorporeal Shock Wave Lithotripsy (ESWL)

ESWL (CPT 50590) uses externally applied sound waves focused on the stone to fragment it into passable particles. It is non-invasive, performed under sedation or light anesthesia in an outpatient setting (hospital outpatient department or ambulatory surgical center), and takes about 45–60 minutes. ESWL works best for stones under 1.5–2 cm in the kidney or upper ureter that are calcium-based and not excessively dense. Uric acid stones, cystine stones, and very dense calcium phosphate stones respond less well.

Medicare Part B covers ESWL for appropriate patients. The Medicare-approved rate is typically in the range of $1,200–$2,500 for the global surgical fee. Your 20% Part B coinsurance comes to roughly $240–$500 in an ambulatory surgical center, potentially more at a hospital outpatient facility. Facility fees are additional.

Ureteroscopy with Laser Lithotripsy (URS)

Ureteroscopy (CPT 52353 with laser, CPT 52352 with basket stone removal) involves passing a thin flexible or semi-rigid scope through the urethra, bladder, and ureter to reach the stone. A holmium laser fiber fragments the stone into dust or small pieces, which are then washed out or removed. URS is now the most common kidney stone procedure for ureteral stones and is increasingly used for renal stones.

The procedure is done under general or spinal anesthesia in an outpatient or ambulatory surgical center. Medicare Part B covers it as a standard outpatient surgical procedure. A temporary ureteral stent (CPT 52332) is often placed at the same time to allow post-procedure swelling to resolve; stent removal (CPT 52310 or 52315) is a separate procedure typically done two to four weeks later, also covered under Part B.

Combined surgical, anesthesia, and facility costs for URS typically range from $5,000–$15,000 before insurance. Under Medicare Part B (20% coinsurance), your out-of-pocket for the physician component alone is often $500–$1,500. Ambulatory surgical center facility fees are lower than hospital outpatient fees; ask your urologist which setting is planned.

Percutaneous Nephrolithotomy (PCNL)

PCNL (CPT 50080 for stones under 2 cm, CPT 50081 for stones 2 cm or larger) is used for large renal stones — typically greater than 2 cm or staghorn calculi (stones that fill the kidney’s collecting system). A surgeon creates a small tract through the patient’s back directly into the kidney and uses a nephroscope and ultrasonic or laser energy to fragment and remove the stone.

PCNL is more invasive than ESWL or URS and typically requires at least one overnight hospital stay, making it a Part A inpatient procedure in most cases. The combined hospital and surgeon cost can exceed $20,000–$40,000, with 20% Part B coinsurance for the surgeon’s fee and the Part A inpatient deductible ($1,736 in 2026) for the facility component. Medigap Plan G covers both.

Ureteral Stents

A stent (small plastic tube) placed in the ureter relieves obstruction and promotes healing after procedures. Stent placement (CPT 52332) and removal (CPT 52310 or 52315) are each separate covered Part B procedures. Patients sometimes need stents before planned surgery if they have an obstructed infected kidney — a urological emergency that requires urgent decompression. Stent-related costs (placement, removal, possible replacement) should be factored into total treatment cost estimates.

Part B: Metabolic Evaluation — Finding Out Why You Form Stones

After a first stone, up to 50% of patients will have a recurrence within 10 years. A thorough metabolic evaluation identifies correctable causes and guides prevention. Medicare Part B covers:

24-hour urine collection: The gold-standard metabolic test for recurrent stone formers. A 24-hour urine collection (CPT codes include 82340 for calcium, 82570 for creatinine, 84133 for potassium, 82542 for oxalate, and others) measures urine volume, calcium, oxalate, citrate, uric acid, sodium, pH, and creatinine. Abnormal results identify hypercalciuria, hyperoxaluria, hypocitraturia, hyperuricosuria, or low urine volume — each with a specific dietary or pharmacologic treatment. Two collections are typically done for accuracy.

Serum parathyroid hormone (PTH): Covered under Part B to evaluate primary hyperparathyroidism as a cause of calcium stones. Elevated PTH drives calcium from bone into the bloodstream and urine, producing hypercalciuria and stones.

Serum uric acid: Elevated in gout and metabolic syndrome; guides uric acid stone prevention.

Coverage note: Medicare Part B covers metabolic testing when ordered as medically necessary for a patient with documented nephrolithiasis. Routine wellness lab panels generally do not include this level of stone-specific testing; your urologist or nephrologist should order it with an appropriate diagnosis code.

Part D: Prevention Medications

Once a metabolic evaluation identifies the stone type and underlying cause, prevention medications are prescribed. These are covered under Medicare Part D — your standalone drug plan or Medicare Advantage drug coverage.

Potassium citrate (Urocit-K): The most commonly prescribed stone-prevention drug. Citrate binds urine calcium, inhibits crystal formation, and raises urine pH, which dissolves uric acid stones and reduces calcium stone recurrence. Generic potassium citrate is widely available and typically Tier 1 or Tier 2 on most formularies, costing $15–$30/month. Brand-name Urocit-K 15 mEq tablets are more expensive; ask your pharmacy to substitute generic.

Thiazide diuretics: Hydrochlorothiazide (HCTZ), chlorthalidone, and indapamide reduce urine calcium excretion and are highly effective for hypercalciuric calcium stone formers. Generic thiazides are among the cheapest drugs in existence — often $3–$10/month — and appear on virtually every formulary at Tier 1. Medicare Part D explained covers how formulary tiers and copays work.

Allopurinol: Reduces uric acid production and is used for uric acid stone formers and some calcium oxalate stone formers with hyperuricosuria. Generic allopurinol (100 mg or 300 mg) is inexpensive — typically $5–$15/month — and well-tolerated. See also Medicare and BPH and overactive bladder where allopurinol for gout-related uric acid stones is discussed in the context of overlapping urological conditions.

Febuxostat (Uloric): A newer xanthine oxidase inhibitor for patients intolerant of allopurinol. The brand-name version is more expensive (Tier 3–4 on many formularies); a generic version is now available and less costly. The $2,100 annual Part D out-of-pocket cap provides backstop protection if placed on a high-tier drug.

Tiopronin (Thiola): Reserved for cystine stone formers — a rare genetic condition causing cystinuria. Tiopronin is a specialty-tier drug and extremely expensive (~$15,000–$20,000 per year at list price). Under the 2026 Part D $2,100 out-of-pocket cap, the patient’s maximum annual drug costs are capped regardless of tier — a meaningful protection for cystinuria patients. See Medicare Part D explained for how the cap works in practice.

Tamsulosin (MET): Alpha blockers used for expulsive therapy during an active stone episode are covered under Part D and very inexpensive as generics. Check if your Part D plan has prior authorization requirements for tamsulosin for a stone indication (vs. BPH).

Medigap vs. Medicare Advantage for Stone Procedures

The right coverage structure significantly changes what you pay for kidney stone surgery.

Original Medicare with Medigap Plan G: After the annual Part B deductible ($257 in 2026), Plan G covers 100% of Part B coinsurance on ureteroscopy, ESWL, and PCNL surgeon fees. For the facility component of PCNL (Part A inpatient), Plan G covers the $1,736 Part A deductible entirely. Your total out-of-pocket for even a complex bilateral PCNL could be as low as $257 — the Part B deductible only.

Original Medicare without Medigap: You pay 20% of all Part B-covered surgeon and facility fees with no annual cap on that coinsurance. A ureteroscopy + laser lithotripsy procedure with facility fees totaling $12,000 would leave you with approximately $2,400 in coinsurance. A PCNL hospitalization could cost considerably more.

Medicare Advantage: Coverage varies by plan. Most MA plans cover kidney stone procedures in-network. Key differences from Original Medicare:

• In-network urologist and facility are required (referral may be needed from your PCP under HMO plans)
• Fixed copays per procedure rather than 20% coinsurance — can be lower or higher than the Medigap/Original Medicare cost depending on the plan
• Out-of-pocket maximum provides a ceiling (typically $5,000–$8,000 in-network for 2026); if you have multiple stone episodes in one year, this cap is valuable
• Emergency coverage is national regardless of plan type — a stone emergency while traveling is covered

See Medicare Supplement vs. Advantage costs for a full comparison of how these structures work.

What Kidney Stones Cost Under Medicare: Summary Table

Costs are approximate 2026 estimates. Actual Medicare-approved rates vary by geographic area and setting.

Seven Steps to Navigating Kidney Stone Care Under Medicare

1. Know your stone type. After your first stone, ask your urologist to send the stone for analysis if it is recovered. Stone composition guides treatment — uric acid stones dissolve with potassium citrate; calcium oxalate stones require different prevention. Without stone analysis, treatment is empiric.

2. Get the metabolic evaluation after a second stone. After a first episode, watchful waiting is reasonable. After a second stone — or after a first stone if it was bilateral, required hospitalization, or you have diabetes or CKD — request a 24-hour urine metabolic evaluation. It is covered under Part B and changes management in the majority of patients.

3. Confirm your procedure will be outpatient. ESWL and routine ureteroscopy are typically done in ambulatory surgical centers. Hospital outpatient departments charge facility fees that may be significantly higher. Ask your urologist which setting is planned and what the estimated total facility bill will be — the difference can be thousands of dollars.

4. Check your Part D formulary for prevention drugs. Before your urologist sends in the prescription, look up potassium citrate, allopurinol, or thiazide diuretics on your plan’s formulary. Generics are almost always Tier 1–2; brand-name equivalents may not be necessary.

5. Ask about the stent. If a ureteral stent is placed, understand when removal is scheduled and that stent removal is a separate procedure with its own copay or coinsurance. Stents left in place too long encrust; they should be removed on schedule.

6. Hydration is the single most important prevention strategy — and it’s free. Increasing urine output to 2.5 liters per day cuts stone recurrence risk by roughly half in most patients. Medicare does not cover hydration coaching, but no prescription is needed. Ask your urologist for your target urine output and follow through.

7. If you have CKD, coordinate your stone care with your nephrologist. Recurrent stone disease is a recognized cause of chronic kidney disease. If your GFR is already reduced, some prevention medications (thiazides, potassium citrate at high doses) require monitoring. See Medicare and chronic kidney disease for how CKD care coordinates with other Medicare coverage.

Frequently Asked Questions

Does Medicare cover lithotripsy for kidney stones? Yes. Extracorporeal shock wave lithotripsy (ESWL) is covered under Medicare Part B as an outpatient procedure. You pay 20% coinsurance after the Part B deductible. Medigap Plan G covers that 20%.

Will Medicare pay for ureteroscopy? Yes. Ureteroscopy with laser lithotripsy (the most common kidney stone removal procedure) is a covered Part B outpatient surgical service. Surgeon, anesthesia, and facility fees are all covered at 80% by Medicare after the deductible. A temporary ureteral stent placed during the same procedure is also covered.

Does Medicare cover kidney stone prevention medications? Yes, under Part D. Generic potassium citrate, thiazide diuretics (hydrochlorothiazide), and allopurinol are all Tier 1–2 drugs on most Part D formularies and cost very little. The $2,100 annual out-of-pocket cap under 2026 Part D rules provides backstop protection even for expensive specialty drugs like tiopronin.

What if I pass a stone at home — does Medicare cover the ER visit? Yes. Emergency department visits for kidney stone pain are covered under Medicare Part B (outpatient) or Part A (if you are admitted as inpatient for more than two midnights). The emergency care is covered regardless of whether a stone is ultimately recovered. Your normal cost-sharing (deductibles and coinsurance) applies.

Can Medicare Advantage deny coverage for kidney stone surgery? MA plans cannot exclude coverage for medically necessary services that Original Medicare covers. However, they can require prior authorization for elective stone procedures, mandate in-network providers, and have their own copay structures. A stone-related emergency is covered at any facility nationwide. Elective ureteroscopy should be scheduled with an in-network urologist to minimize your costs.

Do I need a referral to see a urologist for kidney stones? Under Original Medicare and most PPO-based Medicare Advantage plans, no referral is needed. Under HMO-based Medicare Advantage plans, a referral from your primary care physician is typically required unless the visit qualifies as an emergency. See Medicare Advantage HMO vs. PPO for how these access rules differ.

Kidney stones are painful and expensive — but Medicare coverage is comprehensive for both the acute episode and long-term prevention. The highest-leverage decisions are getting the metabolic evaluation that identifies the underlying cause, using the cheap generic prevention drugs that actually work (potassium citrate, thiazide diuretics, allopurinol), and choosing the right coverage structure for potentially recurring surgical procedures. If you carry Medigap Plan G, a ureteroscopy that might otherwise cost $1,500 out of pocket costs you the annual deductible only. That difference compounds with every recurrence. See Medigap plans compared and Medicare Savings Programs if cost protection or low-income assistance are priorities.