What Causes Medical Coding Revenue Leakage, and How Can Teams Address It?

When I worked in revenue integrity, the question was whether the account accurately reflected the documented care. Were the right charges, codes, and modifiers present? Had anything been missed?

Medical coding revenue leakage occurs when coding or charge capture gaps cause a provider to miss appropriate reimbursement. A documented procedure may never generate a charge, or an assigned code may fall below what the documentation supports.

An encounter can move through its charging workflows and still be incomplete. Understanding how those gaps arise is the first step toward preventing them.

How separate coding and charge workflows create gaps

Codes and charges can reach the same hospital encounter through several workflows. Four common examples are:

1. Provider or nursing charge entry. A clinician enters a charge linked to a predefined code.
2. Order or result completion. A configured EHR event triggers a charge from the chargemaster, or CDM.
3. Coder-entered CDM charges. A coder manually adds a charge with a predefined code.
4. Documentation-based code assignment. A coder reviews the record to determine the appropriate code, such as an E/M level.

The first three involve hard-coded charges: the code is already linked to the CDM entry, even when a person initiates the charge. Soft coding involves assigning codes based on documentation review.

These workflows vary by organization and care setting. In an emergency department, several may contribute to one encounter, so successful charge capture in one workflow can coexist with a missed charge in another.

Two ways documented care gets missed

1. A service never generates the expected charge. A bedside procedure is documented, but the charge-entry step is missed. A completed service does not trigger its expected charge. A CDM mapping changes, interrupting a previously reliable process. Other charges may already be on the account. Their presence does not establish that every applicable service was captured.
2. Coding does not fully reflect the documentation. An E/M level may fall below the level supported by the record and applicable criteria. Injection and infusion rules may be applied inconsistently, leaving a supported service unreported.

Documentation review helps distinguish a missing charge from an incorrectly selected code, so teams can determine whether to repair a charging workflow or address coding practice. Differences in E/M distributions can prompt that review, but do not establish undercoding on their own.

Why missing charges may not appear in denial or underpayment reports

Denial and underpayment reports help teams identify problems with services that were billed. A documented service left off the claim may generate neither a denial nor an underpayment flag.

The claim may be paid as submitted while the omitted service goes unnoticed. Finding that gap requires comparing the documented care with the codes and charges captured.

Pre-bill reconciliation, exception controls, and retrospective audits can help identify omissions. The next step is determining whether those findings lead only to a corrected account or also to a fix that prevents the same gap from recurring.

How revenue integrity teams can address recurring gaps

• Map charge capture responsibilities. In NAHRI’s 2026 industry survey, 51% of respondents reported a formal charge reconciliation policy. (1) Establish how each service should generate a charge, who monitors the workflow, and who investigates omissions.

• Review completeness alongside correctness. Compare the documentation with the codes and charges on the encounter. Ask both whether existing entries are supported and whether a reportable service is missing. Where feasible, perform these checks before billing.

• Investigate the cause of recurring discrepancies. Determine whether the issue involves documentation, charge entry, EHR configuration, or coding practice. Correcting one account leaves the next encounter exposed if the underlying configuration or coding practice stays unchanged. A 2025 UNC hospitalist study found that a standardized documentation template improved capture of physician work more effectively than education alone. (2) Documentation fixes may require clinical, coding, CDI, and revenue integrity collaboration.

• Check that the correction holds. Review subsequent encounters to confirm that the discrepancy has stopped recurring. When measuring recovered revenue, account for applicable payment arrangements rather than treating the value of added charges as an equivalent increase in reimbursement.

How Nym helps address coding-related revenue leakage

The gaps described above share a common problem: the codes and charges on an account do not fully reflect the documented care. Nym’s AI-powered autonomous medical coding engine uses Clinical Language Understanding (CLU) technology to translate clinical documentation into codes, helping capture services that might otherwise be missed.

Nym assigns both hard-coded charges and soft codes associated with CPT/HCPCS. That matters when a service is documented but the expected charge was never entered: the documentation provides the basis for coding the service. The engine also applies coding logic consistently to the encounters it codes, helping reduce variation in how documented care is translated into codes.

Encounters Nym completes autonomously move to billing without human review, giving coders more time for encounters that need their judgment. When documentation is missing, coding and clinical teams still need to resolve the gap before the affected service can be coded.

Revenue integrity teams also need to understand why a code was assigned. Nym’s audit trail connects each assigned code to supporting documentation and guidelines. (2) Teams can use that evidence during their reviews to assess coding decisions and investigate discrepancies, then work with the appropriate department to address the underlying cause.

At Inova, implementation of Nym for ED facility coding was associated with a 10% increase in average charges per ED encounter. The result illustrates why documentation-supported coding matters to revenue integrity: more complete capture can reveal opportunities that are easy to miss when an account already appears complete.

Sources

1. National Association of Healthcare Revenue Integrity (NAHRI). 2026 State of the Revenue Integrity Industry Report. June 1, 2026. See pages 13–15 for charge reconciliation responsibilities and policies.
2. Howard-Williams E, Knight R, Ossman P, et al. A fiscally sound, evidenced-based solution to conquering the complexity of physician billing guidelines: A physician-centric note template. Health Information Management Journal. Published online January 30, 2025. doi:10.1177/18333583241309990.