Coinsurance

Extended Definition

Coinsurance is the percentage of costs you pay for a covered healthcare service after you’ve met your deductible. It’s different from a copay, which is a fixed dollar amount.

How Medicare Coinsurance Works

After meeting your $240 Part B deductible:

• Medicare pays 80% of the approved amount
• You pay 20% coinsurance

Example - HA Injection:

• Medicare-approved amount: $400
• Medicare pays: $320 (80%)
• Your coinsurance: $80 (20%)

Coinsurance vs. Copay

Feature	Coinsurance	Copay
How it’s calculated	Percentage	Fixed dollar amount
Varies by service cost	Yes	No
Common with	Medicare, many plans	Medicare Advantage
Example	20% of $400 = $80	$40 flat fee

Managing Coinsurance Costs

Medigap (Medicare Supplement) Plans:

• Plans G, F, and others cover Part B coinsurance
• You pay a monthly premium
• Services have $0 coinsurance
• Provides cost predictability

Medicare Advantage:

• Replaces coinsurance with copays
• Costs vary by service type
• May have out-of-pocket maximum

Calculating Your Costs

To estimate your coinsurance:

1. Find the Medicare-approved amount for the service
2. Confirm you’ve met your deductible
3. Multiply by your coinsurance percentage (usually 20%)

Resources:

• Medicare.gov procedure price lookup
• Call your provider’s billing department
• Use our cost calculator tool

Important Notes

• Coinsurance is based on approved amount, not billed amount
• Using non-participating providers may cost more
• Some services have different coinsurance rates
• Medigap premiums may save money long-term