Everyone loves to read the general guidelines at the front of the ICD-10 book, right? No? Well, here’s an important excerpt.

“Code all documented conditions, which coexist at the time of the visit that require or affect patient care or treatment. (Do not code conditions, which no longer exist).”

Most of the articles I’ve written have focused on the first sentence in this guideline. This article will focus on the second.

“Do not code conditions which no longer exist.”

That sounds fairly straightforward, doesn’t it? If the patient had appendicitis and a surgeon removed the appendix, then the patient no longer has appendicitis. If the patient had an ankle fracture four years ago and is seen today, the patient no longer has an ankle fracture. These examples are straightforward.

There is more confusion in selecting codes for cancer surveillance visits or for patients who have had a stroke or a transient ischemic attack (TIA). In the case of stroke, selecting the incorrect code raises the risk score for that patient and for the physician’s panel of patients. Since future payments in risk contracts are based on acuity, incorrectly reporting these conditions is a compliance issue.

Coding malignant neoplasms in ICD-10

Let’s start with malignant neoplasm.

The ICD-10 guideline at the front of the book says this.

“When a primary malignancy has been previously excised or eradicated from its site and there is no further treatment directed to that site and there is no evidence of any existing primary malignancy, a code from category Z85, personal history of malignant neoplasm, should be used to indicate the former site of the malignancy. Any mention of extension, invasion, or metastasis to another site is coded as a secondary malignant neoplasm to that site. The secondary site maybe the principle or first-listed with the Z85 code used as a secondary code.”

The short form of that guidance is this: do not report malignant neoplasm if the patient either has no evidence of the disease or is not receiving treatment. In that case, use personal history of malignant neoplasm. The length of the typical surveillance period is not a factor in determining whether to use malignant neoplasm or personal history of malignant neoplasm. Leukemia and lymphoma codes are report with “in remission” codes from Chapter 2.

If a patient is still receiving any treatment for the cancer, including hormone treatment, continue to use the malignant neoplasm code.

And, for a patient who had a polyp removed a prior colonoscopy, the code for a re-visit or colonoscopy in later years isn’t colon polyp K36.5 but personal history of colonic polyps, Z86.010.

Coding for stroke (cerebral accident) in ICD-10

Stroke and TIA are often miscoded in medical records as current conditions, when the condition is not current. In fact, this mistake is so common, groups should consider setting up an edit if the diagnosis code for acute stroke is reported for an office visit. Often, the patient comes to the medical practice after having been seen in the hospital or the emergency department for a stroke or TIA. In that case, if the patient is not currently experiencing one of those conditions, use code Z86.73, personal history of transient ischemic attack and cerebral infarction without residual deficits.

A patient who has residual deficits from a stroke should be coded with the code from category I69.-, sequel of cerebral infarction. Not all codes in category I69 have a risk adjustment score, but monoplegia, hemiplegia and other paralytic sequelae do. TIAs do not risk adjust.

Myocardial infarction is coded based on whether the condition is considered current or not. ICD-10 considers current to be an MI that occurred within the last 28 days.

Malignant neoplasms, strokes, monoplegia or hemiplegia as a result of a stroke risk adjust, while personal history of malignant neoplasm does not. Neither TIA nor personal history of TIA have a risk adjustment score. Current MI codes do risk adjust, but old MI does not. If the patient has other cardiac conditions that are addressed at the visit, do add those to the claim form. Often, the patient has coronary artery disease, and if addressed at the visit, it is correct to add that code.

Compliance Issues

Compliance Issues
	Do not use	Use
Patient seen in office, follow up for stroke	I63.- Cerebral infarction	I69.- Sequelae of cerebral infarction Z86.73 Personal history of transient ischemic attack (TIA), and cerebral infarction without residual deficits
Patient seen in office, follow up for TIA	G45.- Transient cerebral ischemic attacks and related syndromes	Z86.73 Personal history of transient ischemic attack (TIA), and cerebral infarction without residual deficits
Patient seen and noted to have “history of XXX cancer” but no current evidence of disease or current treatment	Code indicating malignant neoplasm, starting with the letter C	Code from category Z85.-, Personal history of malignant neoplasm
Patient seen > 28 days after an acute MI	I20.-, I21.-, I22.- Current MI	I25.2 Old myocardial infarction

OIG HHS report, November, 2022 A-09-19-03001

The OIG and CMS are paying attention to Medicare Advantage Plans diagnosis coding. MA Plans are paid varying amounts for Medicare beneficiaries based on age, gender, living at home/living in a facility, geography and medical conditions. The medical conditions are communicated to Medicare via claims and supplemental files by Medicare Advantage plans, and set the rate for the beneficiary for the following year.  It is highly profitable for insurance companies to administer these MA Plans.

The OIG looked at one MA Plan, California Physicians’ Service, Inc and found that over a two year period the plan was overpaid by at least $2 million for a set of high risk diagnosis codes. You can read their 50 page report for yourself  https://oig.hhs.gov/oas/reports/region9/91903001.asp  And, if you have questions about how MA plans work, the background explanation on pages 2-6 explains it all. I wish my own writing was that clear and concise.

Findings

The OIG looked at diagnosis codes in six groups: acute stroke, acute heart attack, acute stroke/acute heart attack combination, embolism, vascular claudication and major depressive disorder. Two of these issues are in my chart, above. Patients with a history of stroke or heart attack were coded as if the condition was acute. There were similar errors for embolism and vascular claudication. There was a low error rate for major depressive disorder.

If your practice has risk contracts, do a self audit of the conditions in the OIG report.

When a practitioner is closing a note and selecting diagnosis codes and types in “stroke,” acute stroke comes up first. It would be worth it to audit diagnosis code I63.- and codes I20.- I21.- and I22.2. These are often honest search mistakes, but they need to be corrected.

Additional resources

The CodingIntel Guide to Hierarchical Condition Categories provides a comprehensive list of HCC and Risk Adjusted Diagnosis Coding resources available on CodingIntel.

Risk coding using the HCC model

Question:

For risk coding using the HCC model, are there diagnosis codes that are riskier than others?

Answer:

Well, yes, there are.

The OIG identified codes in six diagnosis categories for a recent review, and five of the six had a high error rate. One common characteristic was assigning an acute code for a condition when the condition was no longer acute. Think acute stroke, acute MI or both. A patient received a diagnosis of embolism, but no anticoagulant drug was prescribed. Or, a patient was assigned a diagnosis code for vascular claudication, but a medication for neurogenic claudication was prescribed. You can see that CMS isn’t just looking at the aggregate claims data, but is also referencing it to their prescription files.

But, don’t just read this Q&A. Scroll up and read the entire article.