Medicare Part B and D Costs in 2025: What Financial Advisors Need to Know

Most retirement plans I see underestimate Medicare costs by $3,000 to $8,000 per year per person. They use $175 a month as a placeholder, apply no IRMAA, skip Part D entirely, and call it conservative. Then the client hits 65, gets their first Medicare bill, and calls wondering what went wrong. The projection wasn't conservative — it was just wrong.

Here are the actual 2025 numbers you need to build projections that hold up.

Part B: The Standard Premium Is Just the Floor

The 2025 Part B standard monthly premium is $185.00, up from $174.70 in 2024. The annual deductible is $257. After the deductible, Medicare pays 80% of covered services — the client pays the remaining 20% with no out-of-pocket cap unless they have a Medigap policy.

That 20% exposure matters more than most people realize. A $50,000 hospitalization creates $10,000 in potential Part B coinsurance. Original Medicare without a supplement is not a complete coverage solution for clients with meaningful assets.

For clients with income above the IRMAA thresholds — based on MAGI from two years prior — the standard premium is just the starting point. The 2025 surcharges for individual filers (based on 2023 income):

• ≤$106,000: $185.00/month — no surcharge
• $106,001–$133,000: $259.00/month — $74.00 surcharge
• $133,001–$167,000: $370.60/month — $185.60 surcharge
• $167,001–$200,000: $481.90/month — $296.90 surcharge
• $200,001–$500,000: $593.20/month — $408.20 surcharge
• Above $500,000: $629.40/month — $444.40 surcharge

Married filing jointly thresholds are approximately double. A client in the third bracket ($133,001–$167,000) pays $370.60 per month for Part B alone — nearly double the standard premium. For a couple where both spouses are on Medicare and both are in that bracket, that's $8,894 per year in Part B premiums before a single medical claim is filed.

Part D: The $2,000 Cap Is the Biggest Change in Years

Starting in 2025, Medicare Part D has a hard out-of-pocket cap of $2,000. Before this year, the catastrophic coverage threshold was tied to total drug costs and effectively sat around $8,000 in out-of-pocket exposure for most clients. That's gone.

For clients on expensive specialty medications — certain cancer drugs, biologics, diabetes medications — this is transformative. A client who was previously spending $5,000–$6,000 out of pocket annually on Part D is now capped at $2,000. That's a real budget change worth flagging in the retirement income plan.

The 2025 Part D maximum deductible is $590, though many plans set it lower. Average Part D premiums vary widely — from under $15/month for basic plans to over $100/month for plans with comprehensive formularies. Most clients should be shopping plans annually using the Medicare Plan Finder during open enrollment (October 15 – December 7), based on their specific medications.

IRMAA applies to Part D as well. The 2025 surcharges for individual filers:

• ≤$106,000: $0 surcharge
• $106,001–$133,000: $13.70/month
• $133,001–$167,000: $35.30/month
• $167,001–$200,000: $57.00/month
• $200,001–$500,000: $78.60/month
• Above $500,000: $85.80/month

Part D IRMAA is added on top of whatever the client pays for their Part D plan premium. A client in the second individual bracket ($106,001–$133,000) pays their plan premium plus $13.70/month — withheld directly from their Social Security benefit if they're already collecting.

Modeling Total Medicare Costs for Clients

The number to build into retirement income projections isn't just Part B — it's the total Medicare cost stack: Part B + Part D + supplemental coverage. Here's what that looks like at different income levels for a 65-year-old individual in 2025:

• Standard income (no IRMAA): $185.00 (Part B) + ~$30 (avg Part D) + $150–$180 (Medigap Plan G) = approximately $365–$395/month
• Second IRMAA bracket ($106K–$133K): $259.00 + $43.70 (plan + surcharge) + $165 Medigap = approximately $468/month
• Third IRMAA bracket ($133K–$167K): $370.60 + $65.30 (plan + surcharge) + $165 Medigap = approximately $601/month

For a married couple both in the third bracket, that's roughly $1,202/month — $14,424/year — in Medicare-related premiums alone, before any cost-sharing.

If the client is considering Medicare Advantage instead of Original Medicare + Medigap, the premium math changes significantly — many MA plans carry a $0 additional premium — but the total cost picture depends heavily on their health utilization. MA plans have copays, coinsurance, network restrictions, and prior authorization requirements that can create unpredictable out-of-pocket costs for clients with complex medical needs. For planning purposes, don't assume $0/month is the right number just because the headline premium is zero.

Late Enrollment Penalties: The Permanent Tax for Waiting Too Long

Medicare's late enrollment penalties are permanent and follow the client for life. Most advisors know they exist. Fewer build a process around catching clients before they trigger them.

Part B: For each 12-month period a client was eligible but didn't enroll, they pay a 10% premium penalty — added permanently to their Part B premium. A client who delays two years pays 20% more for Part B every month for the rest of their life. On the 2025 standard premium, that's an extra $37/month, or $444/year, forever.

Part D: The penalty is 1% of the national base beneficiary premium (approximately $36.78 in 2025) for each month of delayed enrollment without creditable drug coverage. A client who goes 24 months without coverage owes a 24% penalty — roughly $8.83/month added permanently to their Part D cost.

The exception for both: clients who are still working and covered under an employer group health plan with 20 or more employees can delay Medicare enrollment without penalty. The clock doesn't start until their employer coverage ends. COBRA and marketplace plans do not count as creditable coverage for purposes of avoiding the late enrollment penalty — clients who leave employer coverage and go on COBRA need to enroll in Medicare within 8 months.

Build a Medicare enrollment checklist into your retirement transition workflow for every client within three years of 65. The Part B enrollment window is 7 months surrounding the 65th birthday (3 months before, the birthday month, 3 months after). Miss it without a qualifying exception and you're waiting until the next General Enrollment Period — January 1 to March 31 — with coverage starting July 1 and a penalty already attached.

Key Takeaways

• The 2025 Part B standard premium is $185/month — use that as your floor, not your estimate; IRMAA and supplemental coverage typically double it or more.
• The new $2,000 Part D out-of-pocket cap is the most significant Part D change in years — update any client with high drug costs whose projections assumed the old catastrophic threshold.
• A couple in the third IRMAA bracket pays over $14,400/year in Medicare premiums alone before any claims — this number belongs in every retirement income projection for high-income clients.
• Part B and Part D late enrollment penalties are permanent; build a Medicare enrollment trigger into your client workflow for anyone approaching 65.
• Clients leaving employer coverage to COBRA need to enroll in Medicare within 8 months — COBRA doesn't restart the clock the way active employer coverage does.
• $0-premium Medicare Advantage plans are not free Medicare — model expected utilization costs before recommending them for clients with ongoing medical needs.