Codes that coincide
I12.9 + I15.0Two codes that can’t be billed together on one claim.
Every pair in the official ICD-10-CM Excludes1 table, over 5,000 rules.
Coding rules and AI review, on every chart.
Cortex Engine v0.8 is what checks each chart in Cortex Lens. Published coding rules catch what payers reject on sight. An AI review reads the rest of the chart and the visit note for what a rule can’t see.
Works inside Practice Fusion. Read-only, so Lens never changes your chart.
In Cortex Lens today
Cortex Engine v0.8
Coding rules
Same chart, same answer, every time.
AI review
Reads the chart and the visit note.
100%right when it flags
89%of issues caught
2.9stypical time per chart
On our benchmark of 10 de-identified real primary-care charts, checked September 28, 2026. How we test
Rules for what payers reject on sight.
Published coding rules, applied the same way on every chart. Each flag explains why.
Side not given
M25.569A code that leaves out left or right, shown with the sided codes to pick from.
Over 2,200 ICD-10-CM codes that have a right and left version.
Kidney disease stage missing
I13.10Hypertensive kidney disease coded without the CKD stage it calls for.
ICD-10-CM asks for an N18 stage code alongside I12 and I13.
Problem list cleanup
The same diagnosis listed twice, or a code that doesn’t fit the patient’s age or sex.
AI review for what a rule can’t see.
The AI reads the problem list, medications, labs, and the visit note when one is open, and says what it relied on.
Two codes that should be one
E11.9 + N18.32 → E11.22Diabetes and kidney disease coded apart when one code covers both.
More specific codes
N18.9 → N18.32An unspecified code your chart can back up, like the CKD stage the latest eGFR supports.
The side, from the note
M25.561When the note says which knee, the right code, with the sentence that supports it.
Only useful flags reach your screen.
- Rules go first. When the AI flags something a rule already caught, you see one flag, with the rule cited.
- One flag per issue. Overlapping findings merge into one, with every fix option kept.
- Coding only. Suggestions to start, stop, or change a medication are removed before you see them.
- Suggestions stay in the same code family as the code on the chart.
- Lens points, your team decides. Nothing changes in Practice Fusion unless a person changes it.
Every version is tested before it reaches Lens.
See the benchmarksA version of Cortex Engine is one set of rules, AI instructions, and AI model. The version number changes only when one of those changes.
Before a new version reaches Lens, it reviews the same de-identified real charts as the one before it, and an independent judge from a different company grades both. The results are public, including the ones that didn’t make the cut.
The benchmark is small: 10 primary-care charts. Visit level and other checks that rely on the visit note are in preview and not yet part of the published score. Results guide product decisions and are not a clinical validation claim.
See Lens on a real chart.
A 20-minute walkthrough with our team.