Medicare is often seen as a safety net for healthcare costs in retirement, but it’s far from free. While you might budget for standard Part B or Part D premiums, you may not realize that certain billing codes—entered during your medical visits—can unexpectedly increase your monthly costs.

These billing codes can influence your Medicare records in ways that lead to premium hikes, especially if they trigger higher income-related surcharges or fall into categories that Medicare treats as ongoing needs. Even worse, you might not even know they’ve been entered unless you check your Medicare Summary Notices (MSNs) or Explanation of Benefits (EOBs).

Let’s uncover 8 of the most common Medicare billing codes that could quietly cost you more.

8 Medicare Billing Codes That Can Raise Your Premium Without Warning

1. Codes for Chronic Condition Management

Medicare allows providers to bill for “Chronic Care Management” (CCM) when you have two or more serious conditions expected to last at least 12 months. While it sounds harmless—after all, it’s meant to coordinate your care—this code can sometimes put you in a higher cost category if it’s tied to more frequent visits or services.

CCM codes may also signal to Medicare that you have ongoing, higher-cost needs, which can impact how your coverage is calculated. If your doctor bills CCM without fully explaining it, you could see your annual healthcare costs rise.

2. High-Level Evaluation and Management (E/M) Visit Codes

Not all doctor visits are billed equally. Medicare uses specific codes for office visits based on complexity and time spent. High-level E/M codes, such as 99214 or 99215, can suggest more severe or complex health issues.

If billed repeatedly, these codes might contribute to your medical spending profile, potentially influencing future premium brackets or increasing your likelihood of triggering the Income-Related Monthly Adjustment Amount (IRMAA). You may not notice the link until your premiums creep upward.

3. Preventive Service Add-On Codes

Preventive care is generally covered without extra costs, but some preventive visits include “add-on” codes for additional counseling, screenings, or lab work. These codes can make the visit appear more expensive and sometimes move you into a different claims category.

Over time, frequent add-on codes, even for well-intentioned extra care, can lead to higher reported annual medical expenses, which may factor into your premiums indirectly.

4. Hospital Observation Status Codes

If you’re kept in the hospital under “observation” rather than being admitted as an inpatient, Medicare bills it differently—often under Part B instead of Part A. Observation billing codes can make your care appear more outpatient-heavy, and certain patterns in these codes can result in higher ongoing costs.

In addition, these codes can trigger extra coinsurance and deductible charges that can push up your total annual spending and impact income-based premium calculations.

5. Physical Therapy and Rehabilitation Codes

Rehabilitation services—whether physical therapy, occupational therapy, or speech therapy—are billed using a variety of CPT codes that Medicare tracks closely. If you require these services frequently, the codes can indicate a long-term need that potentially impacts premium tiers.

Even if your therapy sessions are short, repeated billing under these codes can show Medicare you’re using more healthcare resources than average, sometimes affecting your overall cost structure.

6. Codes for Durable Medical Equipment (DME)

From wheelchairs to oxygen equipment, DME comes with its own set of billing codes. If these codes appear often, Medicare may classify you as having ongoing medical equipment needs, which can lead to higher reported healthcare usage.

What’s more, some DME codes trigger rental charges that continue month after month, meaning your annual spending profile—and possibly your premiums—keep climbing without you realizing why.

7. Advanced Imaging Codes

Tests like MRIs, CT scans, and PET scans are billed under high-cost imaging codes. If these appear on your Medicare record regularly, it can make you look like a higher-cost patient in the system’s eyes.

While medically necessary imaging is important, unnecessary or repeated scans can raise red flags. They might not directly change your premium overnight, but when combined with other high-value codes, they can tip you into higher cost categories.

8. Mental Health and Behavioral Therapy Codes

Medicare now covers more mental health services than ever before, including counseling and psychiatric visits. While this is a positive shift, these services are billed under specific codes that may indicate recurring, higher-cost treatment plans.

If you receive ongoing therapy, especially with add-on services or group counseling codes, it can increase your total billed costs for the year. In some cases, this can influence income-related premium adjustments.

How These Codes Affect Your Premiums

While most people assume their Medicare premiums are only tied to their income, billing codes can play a role in two ways:

1. Triggering IRMAA: The Income-Related Monthly Adjustment Amount is based on your reported income, but certain high-cost patterns in billing can influence what’s reported or how your income is calculated for Medicare purposes.
2. Flagging Higher Utilization: Medicare tracks “utilization patterns” to predict your healthcare needs. If your records consistently show high-cost codes, it can impact your premiums indirectly through plan changes, supplemental plan costs, or adjustments in Part D drug coverage.

In short, billing codes alone won’t always spike your premium, but when combined with other factors, they can tip the scales.

How to Protect Yourself from Code-Related Premium Hikes

The good news is that you have some control over how these codes affect you. Here’s how:

• Review your Medicare Summary Notices (MSNs) regularly: Look for unfamiliar codes and ask your provider to explain them.
• Question add-on services: If your doctor recommends extra screenings or tests during a visit, ask if they’re medically necessary or optional.
• Understand your plan’s coverage: Some Medicare Advantage plans are more sensitive to high-cost codes than Original Medicare.
• Keep your providers informed: Make sure all your healthcare providers know what’s already been billed to avoid duplication.
• Appeal incorrect charges: If you see a code that doesn’t match the care you received, file a correction request promptly.

The Bottom Line on Medicare Billing Codes and Premiums

Billing codes might seem like a behind-the-scenes detail, but they can have a ripple effect on your Medicare costs. While most healthcare providers use them appropriately, even legitimate codes can contribute to higher premiums if they appear too often or are layered with other high-cost services.

By staying informed, reviewing your records, and asking questions, you can reduce the risk of unexpected premium hikes and maintain more control over your healthcare spending.

Protecting Your Medicare Premiums from Hidden Traps

If you’re in retirement, every dollar counts, and unexpected premium increases can throw off your budget. Understanding how Medicare billing codes work is a powerful step toward safeguarding your finances. With proactive monitoring and open communication with your healthcare providers, you can spot potential cost traps early and keep your premiums as low as possible.

Have you ever caught an unusual Medicare billing code on your statement before it caused a bigger problem? What happened when you brought it up?

Read More:

10 Medicare Decisions That Can’t Be Reversed

7 Things Medicare Won’t Pay for (And Most People Don’t Realize)

Riley Jones

Riley Jones is an Arizona native with over nine years of writing experience. From personal finance to travel to digital marketing to pop culture, she’s written about everything under the sun. When she’s not writing, she’s spending her time outside, reading, or cuddling with her two corgis.