One stain across several levels

Read an original fictional chart, identify the supported facts, and explain your coding workflow.

Chart gym · Original fictional record

Service date: 2026-09-09 · Outpatient laboratory; Medicare reporting relationship

Use your code books and write your reasoning before opening the walkthrough. This exercise contains no real patient information.

Pathology specimen

Fictional tissue from one lesion is submitted for examination. The laboratory prepares one tissue block relevant to this exercise. The pathologist orders a particular special stain to assess the submitted tissue; the stain is medically necessary.

Preparation log

Several deeper levels are cut from that same block. The same special stain is applied to each level. The log also records a control used to check the staining procedure. No additional patient specimen or second tissue block is involved.

Interpretation

The pathologist reviews the stained levels together in the specimen’s assessment. The record does not describe different stain procedures or another block needing an independently necessary application. Slide identifiers distinguish preparations within this one-block sequence.

Claim review

The draft counts each stained level and the control as separate patient units. Apply the cited special-stain rule. Do not transfer the answer automatically to immunohistochemistry or other methods with different defined units.

Your coding worksheet

Count the relevant patient blocks.
Identify whether the stain changes between levels.
Evaluate units for levels and controls.
State the method-specific limit of the conclusion.

In your notebook, record the supported facts, your index route, the instructions you checked, and any missing detail that limits your answer.

Compare with the worked explanation

One patient tissue block is involved.
The same special stain is used at each level.
NCCI M.9 permits one unit for that stain on the block; extra levels and controls do not add units.
Other methods require their own entry and unit rules.

Reference sections: M.9

Practice the linked chart questions