But, chances are, you are already up to your eyebrows in SOAP notes, ICD-10s, and exponentially changing billing guidelines. Internal medicine billing is not a paper task alone, but a survival discipline. Whether you’re a physician, billing specialist, or managing the business side of a practice, you know how tricky this space can be.
2025 didn’t come quietly. From subtle CPT shifts to new E/M guidelines and reimbursement tweaks, internal medicine billing has evolved in ways that could mean lost revenue if you blink too long. Let’s break it all down in this multi-part guide—without robotic fluff, just real insights you can use.
CPT and ICD-10 Codes Every Internal Medicine Practice Should Know in 2025
Internal medicine covers a wide scope—diabetes, hypertension, infections, chronic conditions, preventive care, and more. That means diverse CPT and ICD-10 codes, and you better believe the 2025 changes are already affecting reimbursement.
Commonly Used CPT Codes in Internal Medicine
| CPT Code | Description | 2025 Notes |
| 99202–99215 | Office or outpatient visits (new & established) | New E/M guidelines emphasize MDM over time |
| 99495–99496 | Transitional care management (TCM) | Bumped up in RVUs; good revenue opportunity |
| 99381–99397 | Preventive visits (age-specific) | Include with G0402 when billing Medicare |
| 99406–99407 | Smoking/tobacco cessation counseling | High audit targets—document thoroughly |
| 99490 | Chronic care management (CCM) | Boosted reimbursement in 2025 |
High-Frequency ICD-10 Codes for Internists
| ICD-10 Code | Condition |
| E11.9 | Type 2 diabetes without complications |
| I10 | Essential (primary) hypertension |
| J06.9 | Acute upper respiratory infection |
| M54.5 | Low back pain |
| F41.9 | Anxiety disorder, unspecified |
Tip: Always match your ICD-10 code to the specificity of the CPT. CMS is cracking down on vague claims in 2025.
Reimbursement Changes in 2025: What Internal Medicine Needs to Know
Here’s the hard truth: CMS is playing hardball with internal medicine this year. While some CPT codes saw an RVU increase, others got slightly trimmed, especially low-complexity visits.
Office Visits Reimbursement Comparison
| CPT Code | 2024 Avg. Medicare Reimbursement | 2025 Avg. Medicare Reimbursement |
| 99213 | $98.25 | $96.10 (slight dip) |
| 99214 | $134.50 | $137.00 (small rise) |
| 99490 | $42.50 | $54.25 (major increase!) |
Observation: Chronic Care Management (CCM) is having a reimbursement glow-up. Internists should capitalize on this shift, especially for patients with two or more chronic conditions.
Coding & Billing Tips You’ll Thank Yourself For
- Don’t undercode your E/M visits — Physicians still downplay complexity. If you’re dealing with 3+ problems and prescription meds, 99214 is often justifiable.
- Split preventive + problem visits carefully — Use modifier -25 if you’re doing both in one appointment. Forgetting it will kill your second claim.
- Use time-based coding if you’re counseling-heavy — 2025’s guidelines allow billing based on total time or medical decision-making (MDM).
- Watch for the new social determinants of health (SDOH) ICD codes — These support complexity and can increase payment in some risk-adjusted models.
FAQ: Internal Medicine Billing in 2025
Q: Can I bill for both a wellness exam and a problem visit on the same day?
A: Yes, if they’re separately documented and medically necessary. Use modifier -25.
Q: What if a patient comes in for diabetes but also has an acute sinus infection?
A: You can list multiple ICD-10s. Make sure your primary diagnosis reflects the chief complaint or primary reason for the visit.
Q: Is telehealth still covered for internists?
A: Yes, with limited CPT codes still reimbursed. Use place of service 02 or 10, and ensure real-time audio-video is used.
E/M Coding in 2025 – Where Internists Gain or Lose the Most
Let’s get real—Evaluation and Management (E/M) coding is where most internists either win or get underpaid. With E/M visits forming the core revenue stream of most internal medicine practices, even tiny mistakes add up to huge financial consequences.
The 2021 E/M overhaul was just the beginning. In 2025, CMS doubled down on its “time or complexity” approach, making it easier in theory but risky in practice if you’re not documenting correctly.
Time-Based vs MDM-Based Coding – What’s Best in 2025?
| Option | What You Focus On | When to Use |
| Time-Based Coding | Total time spent with the patient | When you’re counseling-heavy or have longer visits |
| MDM (Medical Decision-Making) | Complexity of diagnosis/treatment | When you’re managing meds, tests, conditions |
Pro Tip: Many internists are still undercoding by habit. If you spend 30+ minutes on a follow-up and are making multiple treatment decisions, that’s a 99214, not a 99213.
E/M Coding Time Reference Table (2025)
| CPT Code | Typical Time Spent (2025) | E/M Level |
| 99213 | 20–29 minutes | Moderate complexity |
| 99214 | 30–39 minutes | Moderate/high complexity |
| 99215 | 40–54 minutes | High complexity |
Keep in mind: only include time spent on the day of the visit—no pre-charting or post-day documentation allowed unless it’s on the same day.
Chronic Care Management (CCM) & Other Value-Added Services
2025 brought some real love to chronic care. Internists treating patients with multiple chronic conditions can bill for Chronic Care Management (CCM) and Principal Care Management (PCM) services with greater reimbursement than ever before.
Chronic Care Codes & Payments (2025)
| CPT Code | Description | 2025 Avg. Payment |
| 99490 | 20 min non-complex CCM | $54.25 |
| 99491 | 30 min complex CCM (by physician) | $86.70 |
| G0511 | CCM in Rural Health/FQHCs | $78.20 |
You don’t need fancy tech—just proper care planning, communication logs, and documentation that proves you spent the time. Capture it all—your notes are your paycheck.
Common Internal Medicine Billing Mistakes in 2025
Even smart practices leave money on the table. Let’s avoid that.
Common Pitfalls
- Skipping Modifier -25: Billing a procedure and E/M visit together? Don’t forget that modifier, or your claim will be denied faster than your coffee gets cold.
- Inaccurate Time Logging: Estimating time or copying generic time phrases like “25 minutes spent” across multiple charts? Auditors are watching closely.
- Underusing Chronic Codes: If you treat patients with multiple conditions, you should be billing 99490 or 99491 regularly.
- Cloning Notes: CMS and private payers are targeting “note cloning.” Each visit should be unique, even if it feels repetitive.
Internal Audit Checklist (Quick Daily Reference)
| Task | How Often? |
| E/M level matches documented time or complexity | Daily |
| Modifiers applied correctly | Per claim |
| ICD-10 specificity is appropriate | Daily |
| Documentation is non-generic | Daily |
| Patient consent for CCM/TCM/PCM | At enrollment |
FAQ Continued: Let’s Clear Up More Confusion
Q: Can I bill 99490 and 99214 for the same patient?
A: Yes, but not on the same day. CCM is billed monthly. The E/M must be separate and not part of your CCM work.
Q: What if a patient doesn’t have Medicare—can I still bill CCM?
A: Absolutely. Many commercial payers follow Medicare’s lead. Check the payer’s policy—you might be surprised how many reimburse.
Q: Is time spent on MyChart messages or prescription refills billable?
A: Yes, under CPT 99421–99423 (digital E/M) or CCM—but it must meet documentation and time requirements.
Telehealth, ICD-10 Updates & Smart Documentation in Internal Medicine Billing (2025)
Remember when telehealth was considered a luxury? In 2025, it’s just part of the game. Internal medicine practices that haven’t woven telehealth billing into their routine are definitely missing out, both in patient retention and revenue.
But here’s the kicker: telehealth isn’t as “anything goes” as it was during the pandemic. Medicare and private insurers have tightened the rules, and coding mistakes are now being flagged more than ever.
Telemedicine Billing in Internal Medicine – 2025 Rules & CPT Codes
Most Common Telehealth CPT Codes in Internal Medicine:
| CPT Code | Description | 2025 Notes |
| 99202–99215 | Office/outpatient visits via telehealth | Still allowed for audio-video only |
| 99421–99423 | Digital E/M (patient portal messages) | Requires cumulative time over 7 days |
| G2012 | Virtual check-in (5–10 mins, brief issue) | Audio-only; some insurers now exclude it |
| G2252 | Extended virtual check-in (11–20 mins) | Useful for symptom follow-ups |
Place of Service (POS) Codes for 2025:
- POS 02 – Telehealth Provided Other than in the Patient’s Home
- POS 10 – Telehealth Provided in Patient’s Home
Modifier 95 still applies to most real-time telehealth visits. Just remember: audio-only visits have limited support in 2025, especially for Medicare.
Smart Documentation: Billing Booster or Audit Trap
Well, the truth is, charting is not enjoyable. However, messy or copy-pasted notes will amount to an invitation to audits in 2025. And the thing about it is? By far, the vast majority of the practices do not even understand that their documentation is costing them money.
Here’s what good documentation looks like now:
2025 Documentation Checklist for Internists
| What to Include | Why It Matters |
| Clear chief complaint | Aligns with CPT selection and ICD use |
| HPI reflecting time or complexity | Required for time-based or MDM billing |
| Assessment + plan with rationale | Especially for 99214/99215 justification |
| Patient education and shared decision-making | Supports moderate/high complexity coding |
| Total time spent (with breakdown, if possible) | Vital for time-based E/M |
Documentation Tip: Use natural language, not templates. Instead of “Patient educated,” write:
“Discussed risks/benefits of increasing metformin. The patient expressed concerns about GI side effects. Agreed to start at 500mg with follow-up in 2 weeks.”
Auditors want authenticity, not robotic phrases.
ICD-10 Coding Updates in 2025 for Internal Medicine
It’s not just CPT codes evolving—ICD-10 is shifting too. 2025 introduced new codes that directly impact internal medicine billing, especially around social determinants, long COVID, and behavioral health overlaps.
2025 ICD-10 Updates Internists Should Know:
| ICD-10 Code | Condition | Notes |
| Z59.82 | Homelessness, unspecified type | Useful for risk-adjusted billing (HCC impact) |
| U09.9 | Post-COVID condition, unspecified | Often missed—can justify higher E/M levels |
| Z91.A4 | Patient noncompliance with therapy due to fear | Helps document the patient refusal context |
| F78.A1 | Mild cognitive impairment, behavioral symptoms | Reflects neuropsychological conditions |
Coding Pro Tip: Start using Z-codes strategically. They won’t boost fee-for-service rates directly, but they affect value-based care metrics and HCC scores, which could tie into future bonuses or penalties.
How to Remain Audit Proof 2025
The reality is that, in 2025, audits are increasing. Either way, whether at Medicare or by private payers, internal medicine is on the hot seat– especially regarding CCM, E/M and time-based codes.
This is your defence policy.
- Internal Medicine Study Guide of Audit Survival
- Never age 99490 without agreement and a plan of care
- Avoid cloning templates in databases, especially pan charts- differentiate the notes on each of them
- Log total time transparently—don’t copy-paste time ranges
- Run internal audits every quarter
- Document all communications, even secure messages and phone calls
FAQs Continued: What Everyone’s Still Asking
Q: Is G2211 (complexity add-on) still reimbursed in 2025?
A: Yes! Use it for visits where patient complexity goes beyond the norm, like managing psychosocial or socioeconomic issues. Add it with 99213/99214 and document why it applies.
Q: Can I use digital E/M codes for MyChart messages from caregivers instead of patients?
A: Yes, if the caregiver is acting on the patient’s behalf and you document the interaction clearly.
Q: What if the patient never shows up, but I already did pre-visit work?
A: No billable code applies unless time was spent communicating directly, or unless you’re using 99453/99454 for remote monitoring setup.
Revenue Wins, Modifier Snares & Smoother Workflows in Internal Medicine Billing (2025)
Billing isn’t just about codes—it’s about timing, logic, and survival. Internal medicine practices in 2025 are juggling packed schedules, high patient complexity, and increasingly picky payers. If you’re not optimizing your workflow and documentation, you’re not just losing money—you’re leaving yourself wide open to audits.
Revenue-Boosting Opportunities You Might Be Missing
Internal medicine billing is full of small wins that compound over time. Many practices are leaving thousands on the table each month simply because they’re too rushed or unaware of the newer codes and billing opportunities.
Use These CPT Codes More in 2025
| CPT Code | Description | 2025 Rate | Why Use It |
| 99490 | Chronic care management (20 mins) | $54.25 | Patients with 2+ chronic conditions |
| G2211 | Visit complexity add-on | $16.30 | Add-on for non-procedural E/M visits (99213–99214) |
| 99441–99443 | Telephone E/M (if allowed by payer) | Varies | Still covered by some insurers |
| 99406–99407 | Tobacco cessation counseling | $15–$29 | Billable in addition to E/M |
| 99473/99474 | Self-measured blood pressure monitoring | ~$10–$15 | Add-on for patients with hypertension |
Tip: Track patients who qualify for G2211 and CCM monthly. Just one of these codes added consistently across 100 patients can change your practice’s bottom line.
Modifier Mayhem: Avoid These 2025 Billing Mistakes
Modifiers can save—or sink—your claims. Many denials in internal medicine come down to modifier misuse. Let’s clean that up right now.
Modifier Cheat Sheet (2025 Edition)
| Modifier | Used For | Common Mistake |
| 25 | Separate E/M on same day as a procedure | Forgetting it when billing a sick visit + vaccine |
| 59 | Distinct procedural service | Using it too freely (can trigger audits) |
| 95 | Telehealth services | Not used for audio-only when required |
| 33 | Preventive service waived from deductible | Missing it for services like screenings |
Real Example: You give a patient a flu shot (90471) and treat their sinus infection (99213). Forget modifier -25? Your E/M claim will likely get rejected.
The Most Common Denial Reasons in Internal Medicine & How to Stop Them
- “Duplicate Services” – You forgot modifier -25 or -59.
- “Medical Necessity Not Met” – Your ICD-10 was too vague or unrelated.
- “Missing Documentation” – You didn’t clearly support the CPT code chosen.
- “Invalid Place of Service” – Used wrong POS for telehealth or home visits.
- “Frequency Limit Exceeded” – Overused wellness or CCM codes without proper intervals.
Fix: Use automated claim scrubbing software before claims go out. Catching these issues up front avoids cash flow bottlenecks later.
Your Ideal Internal Medicine Billing Workflow in 2025
Let’s simplify it. Here’s what a smooth billing process should look like from start to finish.
2025 Internal Medicine Billing Workflow
| Step | Best Practice |
| Appointment scheduled | Pre-check eligibility, preventive due dates, CCM flags |
| Visit conducted | Use time/MDM to determine E/M level + document complexity |
| Coding | Apply CPT + ICD-10 + modifiers accurately |
| Claim review | Use clearinghouse to detect bundling or missing data issues |
| Submission | Send claims same day or within 24–48 hrs max |
| Denial management | Weekly review + appeals with corrected info |
| Monthly audit | Review 10–15 charts for coding accuracy |
Quick Win: Identify top 10 payers and build custom cheat sheets for their quirks (POS codes, denial reasons, frequency limits). This will save so much time and rework.
FAQ: Billing Logic That Gets Asked Again and Again
Q: If I see a patient for diabetes but also refill their BP meds, can I bill a higher E/M level?
A: If your medical decision-making increased due to multiple conditions and active management—yes. Just document everything clearly.
Q: Can I bill G2211 every time I see a complex patient?
A: Not blindly. You need to document why the visit was more complex than usual, especially in behavioral or social terms.
Q: How do I know if a service is bundled or separately billable?
A: Use the NCCI edits tool (National Correct Coding Initiative) or a billing software that flags this. Many services (like EKG + visit) can be billed together with the right modifier.
Payer Nuances, Superbill Setup & Billing Survival Strategies for 2025
Internal medicine billing is not uniform across all insurers. Each payer—including Medicare, Medicaid, and commercial carriers—has its own coding, documentation, and modifier requirements. Practices must account for these variations to minimize rejections and ensure timely payments.
Key Differences Among Major Payers (2025)
| Payer | Key Considerations |
| Medicare | Accepts most E/M codes and chronic care services (CCM, TCM). Strict documentation audit. |
| Medicaid | Requirements vary by state; many states adopted G2211 and remote monitoring codes. |
| Commercial | United, Cigna, Aetna, and BCBS often follow Medicare, but with unique modifier rules. |
| Tricare | Accepts telehealth with POS 10 but excludes some E/M complexity add-ons like G2211. |
Recommendation: Maintain a billing matrix per payer, noting coverage limitations, modifier rules, and documentation expectations. This avoids repeat denials.
Sample Superbill Format for Internal Medicine – 2025
A well-designed superbill streamlines coding accuracy. Below is a simplified layout tailored for internal medicine practices.
CPT Code Section:
| Visit Type | CPT Code |
| New Patient Visit (Level 2–5) | 99202–99205 |
| Established Visit (Level 2–5) | 99212–99215 |
| Preventive Visit (age-based) | 99385–99397 |
| Chronic Care Management | 99490, 99491 |
| Telehealth Visit | 99213–99215 + Modifier 95 |
| Tobacco Cessation Counseling | 99406, 99407 |
ICD-10 Codes Section:
| Common Diagnoses | ICD-10 Code |
| Hypertension | I10 |
| Type 2 Diabetes | E11.9 |
| Hyperlipidemia | E78.5 |
| Depression | F33.1 |
| Long COVID/Post-COVID | U09.9 |
| Obesity | E66.9 |
Note: Update the superbill quarterly to reflect code additions, deletions, or payer-specific requirements.
2025 Billing and Coding Compliance Checklist
To maintain efficiency and reduce errors, implement the following monthly and quarterly audits.
| Action Item | Frequency |
| Internal chart audits (10% random sample) | Monthly |
| Payer-specific policy update reviews | Quarterly |
| CPT/ICD code revisions tracking | Annually |
| Modifier usage accuracy assessment | Monthly |
| Denied claims root-cause analysis | Biweekly |
Implementing these steps supports regulatory compliance and revenue integrity.
Summary: Key Takeaways for Internal Medicine Billing in 2025
- Use Time-Based E/M Coding Wisely – Ensure total time is documented clearly and reflects medical necessity.
- Leverage Complexity Add-Ons (e.g., G2211) – Only when supported by documentation involving behavioral, social, or multiple comorbidities.
- Expand Chronic and Remote Monitoring Services – Services like 99490, 99491, 99457, and 99458 are underutilized and now better reimbursed.
- Payer-Specific Billing Policies: There continues to be differences between Medicare, Medicaid, and commercial insurers that are a big cause of denials.
- Prevent Common Modifier -25 and -59 Errors – Modifier -25 and -59 remain one of the commonest causes of audit and denial.
- Stress Clean Documentation – Only on a personal basis, make notes, get time logs, proper medical decision-making clarity, and appropriate ICD-10 specificity.
Internal medicine billing in 2025 is increasingly nuanced. Nevertheless, through disciplined coding protocols, tapping into new opportunities such as G2211 and CCM services, and the adherence to rigorous compliance pipelines, practices are capable of maximizing reimbursement with the least degree of risk. In order to get detailed and updated information about medical coding and billing, go through other articles on the website, and don’t forget to ring “Medstar Billing Services” to get a hundred percent accurate reimbursement for your services.
