Under Original Medicare, Part B (outpatient care, many doctor services, preventive services rules, durable medical equipment categories, and more) generally starts each year with a Part B deductible. You pay that annual deductible amount for covered Part B services before Medicare begins its usual share; after the deductible, you typically owe 20% coinsurance of the Medicare-approved amount for many services if you have no supplemental coverage. This page is deductible orientation—not IRMAA premiums (Medicare IRMAA basics), not Part B excess charges, and not Advantage MOOP math.
General deductible vocabulary: Health insurance deductibles. Bill and EOB habits: Medical bills and insurance.
Part B deductible vs nearby Medicare costs
| Cost | What it is | Where it shows up |
|---|---|---|
| Part B premium | Monthly amount (standard or IRMAA-adjusted) | Usually deducted from Social Security or billed |
| Part B deductible | Annual amount you pay for covered Part B services before Medicare’s share on those services | Medicare Summary Notice (MSN) / claims |
| Part B coinsurance | Often 20% of the approved amount after deductible (many services) | Same MSN trail |
| Part B excess charges | Possible extra from some non-participating providers | Separate from the deductible (excess charge basics) |
| Part A deductible | Inpatient benefit-period deductible | Different benefit; do not mix with Part B (Part A benefit period basics) |
CMS publishes the Part B deductible dollar amount each calendar year—use Medicare.gov or your MSN for the figure that applies to your year, not a memorized blog number. Some preventive services are covered at $0 when requirements are met; others still interact with deductible/coinsurance rules—check the specific service.
How Medigap usually interacts
Standardized Medigap letters differ on whether they pay the Part B deductible:
| Pattern (orientation) | Typical letter examples (verify outline) |
|---|---|
| Covers Part B deductible | Plan F (generally closed to newly eligible people); some other legacy charts |
| Does not cover Part B deductible; still helps coinsurance / other gaps | Plan G is widely discussed this way for newly eligible cohorts—confirm your state’s chart |
| Copay-style designs | Plan N and others use different patient-pay structures |
Medigap premiums (UnitedHealthcare, Humana, Mutual of Omaha, regional Blues, etc.) are separate from the Part B deductible itself. Shop letters during guaranteed-issue windows when you can: Medigap open enrollment basics.
Medicare Advantage plans use plan deductibles, copays, and MOOP instead of pairing with Medigap; do not apply Original Medicare Part B deductible assumptions to an Advantage EOC without reading it.
Worked example: $240 deductible then 20% coinsurance
Drew has Original Medicare, no Medigap yet, and has paid $0 toward the Part B deductible this year. Illustrative CMS deductible for Drew’s year is $240 (placeholder—use the official figure for your year). Drew receives covered outpatient specialist services with a Medicare-approved amount of $1,000 (participating provider, assignment accepted).
| Slice | Illustrative amount |
|---|---|
| Applied to Part B deductible | $240 (Drew pays) |
| Remaining approved amount | $760 |
| Medicare pays ~80% of remaining | ~$608 |
| Drew’s 20% coinsurance on remaining | ~$152 |
| Drew’s total for this claim | ~$392 before any other bills |
If Drew instead had a Medigap letter that covers the Part B deductible and Part B coinsurance per its outline, Drew’s patient-pay on this claim could drop to $0 for those slices after Medicare processes—while Drew still pays the monthly Medigap premium. If Drew had Plan G–style coverage that skips the Part B deductible but covers coinsurance, Drew might still pay the $240 deductible once per year, then have coinsurance filled per the policy.
Always trust the MSN numbers over a blog table.
Practical habits
- Look up the current-year Part B deductible on Medicare.gov each January.
- Track deductible progress on MSNs; reset is annual for Part B.
- Ask whether a service is preventive $0 or deductible/coinsurance-eligible.
- Compare Medigap outlines specifically for “Part B deductible” yes/no.
- Prefer participating providers to avoid mixing deductible math with excess charges.
- If on Advantage, use that plan’s deductible/MOOP rules—not this Original Medicare table.
Checklist
- Confirm Original Medicare (A + B) vs Advantage before applying these rules.
- Note this year’s official Part B deductible amount.
- Read your Medigap outline for deductible coverage—or confirm you have none.
- Save MSNs until deductible and coinsurance match your records.
- Budget IRMAA separately if it applies to your premium.
- Re-shop supplemental coverage only with current letter charts and SHIP help.
Hospital observation often bills under Part B instead of Part A: Observation status vs inpatient basics.
Outpatient PT/OT/SLP therapy thresholds and the KX modifier (separate from the Part B deductible): Medicare outpatient therapy threshold basics.
High-deductible Plan G stacks a separate Medigap deductible layer: High-deductible Medigap Plan G basics.
Educational only. Not insurance, tax, or legal advice. Not a plan recommendation. Part B deductible amounts, preventive-service rules, Medigap letter benefits, and Advantage designs change; confirm with Medicare.gov, your state SHIP program, and insurer outlines of coverage.